A webmaster is a person responsible for designing, developing, marketing, or maintaining Web site(s). The term webservant is sometimes used when the person is providing such services to a church or charity. The webmaster of a Web site may also be called a system administrator, the author of a site, or the Web site administrator.Web site traffic
The amount of visitors and visits a Web site receives.
Sunday, November 26, 2006
What is a web service ?
A web service is a collection of protocols and standards used for exchanging data between applications or systems. Software applications written in various programming languages and running on various platforms can use web services to exchange data over computer networks like the Internet in a manner similar to inter-process communication on a single computer. This interoperability (e.g., between Java and Python, or Windows and Linux applications) is due to the use of open standards. ...
What is web hosting ?
Web hosting is a service that provides Internet users with online systems for storing information, images, video, or any content accessible via the web. Web hosts are companies that provide space on a server they own for use by their clients as well as providing Internet connectivity, typically in a data center. Web hosts can also provide data center space and connectivity to the Internet for servers they do not own to be located in their data center.
What is web development ?
Web development incorporates all areas of creating a Web site for the World Wide Web. This includes Web design (graphic design, XHTML, CSS, usability and semantics), programming, server administration, content management, marketing, testing and deployment. The term can also specifially be used to refer to the "back end", that is, programming and server administration. There are usually more than one member that works on a given Web Development team, each specialising in his or her own field.
What is web design ?
Web design is the design of web pages, websites and web applications using HTML, CSS, images, and other media.
Web design is in contrast with web development, which includes web server configuration, writing web applications and server security.A website is a collection of information about a particular topic or subject. Designing a website is defined as the arrangement and creation of web pages that in turn make up a website. A web page consists of information for which the website is developed. For example, a website might be compared to a book, where each page of the book is a web page.
A website typically consists of text and images. The first page of a website is known as the Home page or Index. Some websites use what is commonly called an Enter Page. Enter pages might include a welcome message, language/region selection, or disclaimer. Each web page within a website is an HTML file which has its own URL. After each web page is created, they are typically linked together using a navigation menu composed of hyperlinks.
Once a website is completed, it must be published or uploaded in order to be viewable to the public over the internet. This is done using an FTP client. Once published, the webmaster may use a variety of techniques to increase the traffic, or hits, that the website receives. This may include submitting the website to a search engine such as Google or Yahoo, exchanging links with other websites, creating affiliations with similar websites, etc.
A relatively new technique for creating websites called Remote Scripting has allowed more dynamic use of the web without the use of Flash or other specialized plug-ins. Leading the various techniques is Ajax, although other methods are still common, as Ajax is not a fully developed standard.
Web design is in contrast with web development, which includes web server configuration, writing web applications and server security.A website is a collection of information about a particular topic or subject. Designing a website is defined as the arrangement and creation of web pages that in turn make up a website. A web page consists of information for which the website is developed. For example, a website might be compared to a book, where each page of the book is a web page.
A website typically consists of text and images. The first page of a website is known as the Home page or Index. Some websites use what is commonly called an Enter Page. Enter pages might include a welcome message, language/region selection, or disclaimer. Each web page within a website is an HTML file which has its own URL. After each web page is created, they are typically linked together using a navigation menu composed of hyperlinks.
Once a website is completed, it must be published or uploaded in order to be viewable to the public over the internet. This is done using an FTP client. Once published, the webmaster may use a variety of techniques to increase the traffic, or hits, that the website receives. This may include submitting the website to a search engine such as Google or Yahoo, exchanging links with other websites, creating affiliations with similar websites, etc.
A relatively new technique for creating websites called Remote Scripting has allowed more dynamic use of the web without the use of Flash or other specialized plug-ins. Leading the various techniques is Ajax, although other methods are still common, as Ajax is not a fully developed standard.
What is Viral Marketing ?
Viral Marketing Defined
What does a virus have to do with marketing? Viral marketing describes any strategy that encourages individuals to pass on a marketing message to others, creating the potential for exponential growth in the message's exposure and influence. Like viruses, such strategies take advantage of rapid multiplication to explode the message to thousands, to millions.
Off the Internet, viral marketing has been referred to as "word-of-mouth," "creating a buzz," "leveraging the media," "network marketing." But on the Internet, for better or worse, it's called "viral marketing." While others smarter than I have attempted to rename it, to somehow domesticate and tame it, I won't try. The term "viral marketing" has stuck.
What does a virus have to do with marketing? Viral marketing describes any strategy that encourages individuals to pass on a marketing message to others, creating the potential for exponential growth in the message's exposure and influence. Like viruses, such strategies take advantage of rapid multiplication to explode the message to thousands, to millions.
Off the Internet, viral marketing has been referred to as "word-of-mouth," "creating a buzz," "leveraging the media," "network marketing." But on the Internet, for better or worse, it's called "viral marketing." While others smarter than I have attempted to rename it, to somehow domesticate and tame it, I won't try. The term "viral marketing" has stuck.
What is video conference & Video streaming ?
Using a computer, video camera, and network such as the Internet, to conduct a live conference between two or more people. Video conferencing is an extremely useful method of communication because it saves people the time and expense of travel and can often accomplish many of the things a physical meeting can. A two-person videoconference is known as point-to-point, while more than two people involved in a session is a multipoint conference.Video Streaming - Refers to displaying images and text on a computer monitor. The video adapter, for example, is responsible for sending signals to the display device.
What is voIP?
VoIP means "Voice over IP" and it is quite simply a way of utilizing the Internet (or even in some cases intranets) for telephone conversations. The primary motivations for doing so are cost and convenience as VoIP is significantly less expensive than typical telephone long distance packages, plus one high speed Internet connection can serve for multiple phone lines.
What is satellite Tv ?
Satellite TV is TV broadcasts delivered via a satellite that is in geostationary orbit 22,000 miles above the Earth. This means that the satellite can maintain its position above a certain place e.g. the ASTRA satellites provide services over Europe.
Signals are beamed up to the satellite from an Earth station, then relayed back down again to be received by a dish.
Satellites can deliver both analogue and digital services, but the benefits of digital transmission have given rise to a move away from analogue.
Signals are beamed up to the satellite from an Earth station, then relayed back down again to be received by a dish.
Satellites can deliver both analogue and digital services, but the benefits of digital transmission have given rise to a move away from analogue.
What is RF (Radio Frequency)?
RF (Radio Frequency)
RF signals are very common in our world, from radio and TV broadcasts to lighting control systems and garage door openers! In all cases radio frequency delivery is utilized whenever signals must travel through the airwaves. Because of the omni-directional nature of RF signals they are useful in home theater remote control systems and centrally-located DSS receivers. You will also find RF input connections on TVs VCRs and DSS receivers. Special RF connections may also be found on laser disc players. These RF connections allow interface with an outboard RF demodulator that is required to derive the Dolby Digital audio tracks from certain laser discs.
RF signals are very common in our world, from radio and TV broadcasts to lighting control systems and garage door openers! In all cases radio frequency delivery is utilized whenever signals must travel through the airwaves. Because of the omni-directional nature of RF signals they are useful in home theater remote control systems and centrally-located DSS receivers. You will also find RF input connections on TVs VCRs and DSS receivers. Special RF connections may also be found on laser disc players. These RF connections allow interface with an outboard RF demodulator that is required to derive the Dolby Digital audio tracks from certain laser discs.
What is DTS (Digital Theater Sound)?
DTS, while similar to Dolby Digital in nature, utilizes a different encoding/decoding process to achieve surround sound reproduction. Although at present the inventory of source material is lagging behind Dolby Digital titles, DTS-encoded programming has proved to be a popular format. A processor and DVD player capable of DTS playback will be required to enjoy this format.
What is Dolby Digital (AC-3) &Dolby® Pro-Logic ?
Dolby Digital (AC-3)
Using a special encoding and decoding process, Dolby Digital allows the movie producer to place full-range dialog, music, and effects anywhere in the listening environment. In order to enjoy Dolby Digital (also know as AC-3) a processor capable of decoding the digital signal must be used. DVD players, Laser Disc Players, DSS receivers, and HDTV set-top boxes are all capable of providing you with the source material for Dolby Digital surround sound.
Dolby® Pro-Logic
Dolby Laboratories developed the process to take two channels of information (stereo) from a source such as a VCR or Laser Disc player, and send it though an electronic network to produce the two additional channels that give us "surround sound". Dolby Pro-Logic is an analog process and will allow us to utilize a center channel for dialog, and two monaural rear speakers. Although a drastic improvement from the original "Dolby Surround," which did not include a center channel, the rear channel information is limited in frequency response and does not allow left to right "panning" in the rear speakers.
Using a special encoding and decoding process, Dolby Digital allows the movie producer to place full-range dialog, music, and effects anywhere in the listening environment. In order to enjoy Dolby Digital (also know as AC-3) a processor capable of decoding the digital signal must be used. DVD players, Laser Disc Players, DSS receivers, and HDTV set-top boxes are all capable of providing you with the source material for Dolby Digital surround sound.
Dolby® Pro-Logic
Dolby Laboratories developed the process to take two channels of information (stereo) from a source such as a VCR or Laser Disc player, and send it though an electronic network to produce the two additional channels that give us "surround sound". Dolby Pro-Logic is an analog process and will allow us to utilize a center channel for dialog, and two monaural rear speakers. Although a drastic improvement from the original "Dolby Surround," which did not include a center channel, the rear channel information is limited in frequency response and does not allow left to right "panning" in the rear speakers.
What are speaker systems terms ?
Speaker Systems Terms
Dipolar Surrounds
Special rear speakers, referred to as Dipoles, are normally placed to the left and right of the listener and radiate sound in a figure eight pattern. The front and back lobes of sound are acoustically out of phase with one another thus placing the listener in an acoustic null. Depending upon your room and your particular system, dipolar surround speakers may achieve a more realistic and seamless surround effect.
LCR (Left, Center, Right loudspeakers)
Every home theater system requires a left, center, and right loudspeaker. These are sometimes referred to as LCRs. The left and right speakers are situated at the far left and right of the projection screen (or beside the TV or rear projection set), while the center channel speaker is situated in the center of the screen (or on top of the TV or rear projection set). Although it is now possible for movie producers to pan audio effects, music, and dialogue to any of the speakers independently, the left and right speakers normally play back effects and music, while the center channel's purpose is primarily dialogue. With Dolby Digital playback systems it is also important that each of the three front speakers are identical models or share the same tonal response.
Rear
Rear speakers in a home theater surround system are normally located behind the listener and are designed to create the illusion that you are acoustically in the middle of the action that is present on your video screen. The placement of these speakers is critical for achieving proper balance and seamless transitions between front and back "panning" of sounds. In most systems only two speakers are required; however, with Dolby Digital surround sound formats the frequency response and tonal quality of the rear speakers should match that of the LCR speakers in your system.
Sub-Woofer
Sub-woofers are special loudspeakers that reproduce audio frequencies that are usually below 120 Hertz. Approximately 80% of the power required to reproduce sounds like explosions are in the frequency bands below 120 Hz. By utilizing a dedicated sub-woofer you are able to increase the performance of your audio system in several ways. Since many sub-woofers include an integral power amplifier, and allow you to remove the low frequency content from the left and right speakers, the A/V receiver or amplification system will now have more power available for the left and right speakers. Sub-woofers are available in many woofer sizes and power ranges and should be selected according to your room size and sound pressure level (SPL) requirements.
Dipolar Surrounds
Special rear speakers, referred to as Dipoles, are normally placed to the left and right of the listener and radiate sound in a figure eight pattern. The front and back lobes of sound are acoustically out of phase with one another thus placing the listener in an acoustic null. Depending upon your room and your particular system, dipolar surround speakers may achieve a more realistic and seamless surround effect.
LCR (Left, Center, Right loudspeakers)
Every home theater system requires a left, center, and right loudspeaker. These are sometimes referred to as LCRs. The left and right speakers are situated at the far left and right of the projection screen (or beside the TV or rear projection set), while the center channel speaker is situated in the center of the screen (or on top of the TV or rear projection set). Although it is now possible for movie producers to pan audio effects, music, and dialogue to any of the speakers independently, the left and right speakers normally play back effects and music, while the center channel's purpose is primarily dialogue. With Dolby Digital playback systems it is also important that each of the three front speakers are identical models or share the same tonal response.
Rear
Rear speakers in a home theater surround system are normally located behind the listener and are designed to create the illusion that you are acoustically in the middle of the action that is present on your video screen. The placement of these speakers is critical for achieving proper balance and seamless transitions between front and back "panning" of sounds. In most systems only two speakers are required; however, with Dolby Digital surround sound formats the frequency response and tonal quality of the rear speakers should match that of the LCR speakers in your system.
Sub-Woofer
Sub-woofers are special loudspeakers that reproduce audio frequencies that are usually below 120 Hertz. Approximately 80% of the power required to reproduce sounds like explosions are in the frequency bands below 120 Hz. By utilizing a dedicated sub-woofer you are able to increase the performance of your audio system in several ways. Since many sub-woofers include an integral power amplifier, and allow you to remove the low frequency content from the left and right speakers, the A/V receiver or amplification system will now have more power available for the left and right speakers. Sub-woofers are available in many woofer sizes and power ranges and should be selected according to your room size and sound pressure level (SPL) requirements.
What is Surround Processor ?
Surround Processor
The term "surround processor" refers to a stand-alone electronic component that would include an audio/video input switching section, a surround sound decoding section, and an output control section. Unlike an A/V receiver, these units do not include an AM/FM tuner or amplifiers for the loudspeaker system. Dedicated surround processors are normally preferred for higher performance systems due to their enhanced electronic circuitry, design features, and their ability to be upgraded to future surround sound formats.
The term "surround processor" refers to a stand-alone electronic component that would include an audio/video input switching section, a surround sound decoding section, and an output control section. Unlike an A/V receiver, these units do not include an AM/FM tuner or amplifiers for the loudspeaker system. Dedicated surround processors are normally preferred for higher performance systems due to their enhanced electronic circuitry, design features, and their ability to be upgraded to future surround sound formats.
What is Power Amplifier ?
Power Amplifier
Power Amplifiers are very simple devices in concept. They take a small signal and increase its power so that a loudspeaker may be connected to its output terminals. Home theater power amplifiers come in many configurations and power ranges. In any system one amplifier "channel" is needed for each speaker in your home theater system. (Note: Some sub-woofers include their own internal power amplifier so you might only require five channels of amplification). Some power amplifiers combine all five or six amplifiers in a single chassis, others, which are sometimes called "mono blocks," will only power a single loudspeaker. How much power do I need? The answer to that question is not simple. It is a complex relationship between the size of your room, the efficiency of your speakers, and ultimately your individual requirements for volume or sound pressure level (SPL). Generally amplifier power outputs of less than 50 watts per channel are considered "low," 50 to 100 watts "medium," and over 100 watts "high."
Power Amplifiers are very simple devices in concept. They take a small signal and increase its power so that a loudspeaker may be connected to its output terminals. Home theater power amplifiers come in many configurations and power ranges. In any system one amplifier "channel" is needed for each speaker in your home theater system. (Note: Some sub-woofers include their own internal power amplifier so you might only require five channels of amplification). Some power amplifiers combine all five or six amplifiers in a single chassis, others, which are sometimes called "mono blocks," will only power a single loudspeaker. How much power do I need? The answer to that question is not simple. It is a complex relationship between the size of your room, the efficiency of your speakers, and ultimately your individual requirements for volume or sound pressure level (SPL). Generally amplifier power outputs of less than 50 watts per channel are considered "low," 50 to 100 watts "medium," and over 100 watts "high."
What is DVD (Digital Versatile Disc) ?
DVD (Digital Versatile Disc)
Originally called the Digital Video Disc, DVD was quickly renamed to include other possible uses of the format such as computer data. The disc is similar in shape and size to an audio Compact Disc and contains a vast amount of information on a single disc. When used for motion pictures, the disc often contains an entire movie in several languages and several screen "aspect ratios". DVDs contain digitally encoded information that requires a special player to decode. DVDs are purchased or may be rented for your enjoyment at home. Major benefits of DVDs include superior audio/video performance, instant access to "chapters" within the movie, and an increasingly vast library of titles.
Originally called the Digital Video Disc, DVD was quickly renamed to include other possible uses of the format such as computer data. The disc is similar in shape and size to an audio Compact Disc and contains a vast amount of information on a single disc. When used for motion pictures, the disc often contains an entire movie in several languages and several screen "aspect ratios". DVDs contain digitally encoded information that requires a special player to decode. DVDs are purchased or may be rented for your enjoyment at home. Major benefits of DVDs include superior audio/video performance, instant access to "chapters" within the movie, and an increasingly vast library of titles.
What is DSS (Direct Broadcast Satellite) ?
DSS (Direct Broadcast Satellite)
Direct Broadcast Satellite Systems allow consumers to access a wide variety of program materials that include movies, sports, music, news, information, educational, and "pay per view" programming. Available from vendors such as DirecTV and Primestar, these signals emanate from satellites in orbit above the earth and are received for use in your home by small "dish" type antennas that are typically about 18" in diameter. In order to receive these signals you must lease or purchase the entire system and pay a subscription fee to be able to view these digital signals. Major benefits of DSS service include superior audio/video performance and freedom of programming choice.
Direct Broadcast Satellite Systems allow consumers to access a wide variety of program materials that include movies, sports, music, news, information, educational, and "pay per view" programming. Available from vendors such as DirecTV and Primestar, these signals emanate from satellites in orbit above the earth and are received for use in your home by small "dish" type antennas that are typically about 18" in diameter. In order to receive these signals you must lease or purchase the entire system and pay a subscription fee to be able to view these digital signals. Major benefits of DSS service include superior audio/video performance and freedom of programming choice.
What is Rear Projection TV ?
Rear Projection TV
Televisions in the 40" to 80" diagonal screen sizes are possible with rear projection TVs and are now available with higher resolution projection tubes and the 16:9 screen aspect ratios required for High Definition TV broadcast standards. Major benefits of this technology include reasonable cost versus screen size and, because of their self-contained construction, allow for their use in rooms with high ambient light levels.
Televisions in the 40" to 80" diagonal screen sizes are possible with rear projection TVs and are now available with higher resolution projection tubes and the 16:9 screen aspect ratios required for High Definition TV broadcast standards. Major benefits of this technology include reasonable cost versus screen size and, because of their self-contained construction, allow for their use in rooms with high ambient light levels.
What is plasma tv ?
Plasma TV
This new technology utilizes a unique display panel that alleviates the need for a cathode ray type picture tube. At the present time this type of TV is somewhat expensive. A major benefit of the plasma display is that it has been sized to accommodate new HDTV 16:9 aspect ratio's and is similar in pixel resolution to a personal computer monitor, thus allowing drastically improved picture clarity.
This new technology utilizes a unique display panel that alleviates the need for a cathode ray type picture tube. At the present time this type of TV is somewhat expensive. A major benefit of the plasma display is that it has been sized to accommodate new HDTV 16:9 aspect ratio's and is similar in pixel resolution to a personal computer monitor, thus allowing drastically improved picture clarity.
What is laser disc ?
Laser Discs were the first high definition audio/video playback medium available for home theater systems. Approximately the size of vinyl long-playing phonograph records, these special discs combine digital audio and video data and require a special laser disc player for interface with the audio system and the video display device. Laser discs, although popular with early-adopting home theater enthusiasts, have never achieved widespread acceptance in the sale and rental markets. Although consumer acceptance has been low to moderate, these discs offer movie lovers several key benefits, including the ability to view films in their original screen aspect ratios, and to enjoy the audio soundtracks in Dolby surround, Dolby Digital, and Digital Theater Sound (DTS) formats.
What is LCD TV & LCD Teconology ?
Liquid crystal display television (LCD TV) is television that uses LCD technology for its visual output. The technology used is generally TFT. It differs from alternate visual output technologies, such as cathode ray tube (CRT) or plasma display (PDP TV).
Early LCD television had drawbacks relative to traditional visual display technologies. It displayed fast-moving action with "ghosting" and could be viewed best only when looking directly at the screen or from a slight angle. These problems have largely been overcome in recent years, and LCD televisions, along with plasma displays, have taken over the dominant market position worldwide from cathode ray displays. The LCD design has the additional advantage of being more efficient in the use of electricity than the CRT design.
For a long time it was widely believed that LCD technology was suited only to smaller sized televisions, and could not compete with plasma technology at larger sizes. This belief has been undermined by the announcements of seventh-generation panels by companies such as Samsung, Sony, LG-Philips LCD, Westinghouse Digital, and Sharp Corporation:LCD technology is based on the properties of polarized light. Two thin, polarized panels sandwich a thin liquid-crystal gel that is divided into individual pixels. An X/Y grid of wires allows each pixel in the array to be activated individually. When an LCD pixel darkens, it polarizes at 90 degrees to the polarizing screens.
This cross-polarizing blocks light from passing through the LCD screen where that pixel has darkened. The pixel darkens in proportion to the voltage applied to it: for a bright detail, a low voltage is applied to the pixel; for a dark shadow area, a higher voltage is applied. LCDs are not completely opaque to light, however; some light will always go through even the blackest LCD pixels.
Early LCD television had drawbacks relative to traditional visual display technologies. It displayed fast-moving action with "ghosting" and could be viewed best only when looking directly at the screen or from a slight angle. These problems have largely been overcome in recent years, and LCD televisions, along with plasma displays, have taken over the dominant market position worldwide from cathode ray displays. The LCD design has the additional advantage of being more efficient in the use of electricity than the CRT design.
For a long time it was widely believed that LCD technology was suited only to smaller sized televisions, and could not compete with plasma technology at larger sizes. This belief has been undermined by the announcements of seventh-generation panels by companies such as Samsung, Sony, LG-Philips LCD, Westinghouse Digital, and Sharp Corporation:LCD technology is based on the properties of polarized light. Two thin, polarized panels sandwich a thin liquid-crystal gel that is divided into individual pixels. An X/Y grid of wires allows each pixel in the array to be activated individually. When an LCD pixel darkens, it polarizes at 90 degrees to the polarizing screens.
This cross-polarizing blocks light from passing through the LCD screen where that pixel has darkened. The pixel darkens in proportion to the voltage applied to it: for a bright detail, a low voltage is applied to the pixel; for a dark shadow area, a higher voltage is applied. LCDs are not completely opaque to light, however; some light will always go through even the blackest LCD pixels.
What are computer viruses, worms, and Trojan horses?
What is a virus?
A computer virus, according to Webster's Collegiate Dictionary, is "a computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data)". Two categories of viruses, macro viruses and worms, are especially common today. Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread is not directly under human control.
Macro viruses
A macro is a piece of code that can be embedded in a data file. Some word processors (e.g., Microsoft Word) and spreadsheet programs (e.g., Microsoft Excel) allow you to attach macros to the documents they create. In this way, documents can control and customize the behavior of the programs that created them, or even extend the capabilities of the program. For example, a macro attached to a Microsoft Word document might be executed every time you save the document and cause its text to be run through an external spell checking program.
A macro virus is a virus that exists as a macro attached to a data file. In most respects, macro viruses are like all other viruses. The main difference is that they are attached to data files (i.e., documents) rather than executable programs. Many people do not think that viruses can reside on simple document files, but any application which supports document-bound macros that automatically execute is a potential haven for macro viruses. By the end of the last century, documents became more widely shared than diskettes, and document-based viruses were more prevalent than any other type of virus. It seems highly likely that this will be a continuing trend.
Worms
Worms are very similar to viruses in that they are computer programs that replicate functional copies of themselves (usually to other computer systems via network connections) and often, but not always, contain some functionality that will interfere with the normal use of a computer or a program. The difference is that unlike viruses, worms exist as separate entities; they do not attach themselves to other files or programs. Because of their similarity to viruses, worms are often also referred to as viruses.
What is a Trojan horse?
Named after the wooden horse the Greeks used to infiltrate Troy, a Trojan horse is a program that does something undocumented which the programmer intended, but that the user would not approve of if he or she knew about it. According to some people, a virus is a particular case of a Trojan horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to a non-replicating malicious program.
For more information on viruses, see the virus-L/comp.virus FAQ at: http://www.faqs.org/faqs/by-newsgroup/comp/comp.virus.html
A computer virus, according to Webster's Collegiate Dictionary, is "a computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data)". Two categories of viruses, macro viruses and worms, are especially common today. Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread is not directly under human control.
Macro viruses
A macro is a piece of code that can be embedded in a data file. Some word processors (e.g., Microsoft Word) and spreadsheet programs (e.g., Microsoft Excel) allow you to attach macros to the documents they create. In this way, documents can control and customize the behavior of the programs that created them, or even extend the capabilities of the program. For example, a macro attached to a Microsoft Word document might be executed every time you save the document and cause its text to be run through an external spell checking program.
A macro virus is a virus that exists as a macro attached to a data file. In most respects, macro viruses are like all other viruses. The main difference is that they are attached to data files (i.e., documents) rather than executable programs. Many people do not think that viruses can reside on simple document files, but any application which supports document-bound macros that automatically execute is a potential haven for macro viruses. By the end of the last century, documents became more widely shared than diskettes, and document-based viruses were more prevalent than any other type of virus. It seems highly likely that this will be a continuing trend.
Worms
Worms are very similar to viruses in that they are computer programs that replicate functional copies of themselves (usually to other computer systems via network connections) and often, but not always, contain some functionality that will interfere with the normal use of a computer or a program. The difference is that unlike viruses, worms exist as separate entities; they do not attach themselves to other files or programs. Because of their similarity to viruses, worms are often also referred to as viruses.
What is a Trojan horse?
Named after the wooden horse the Greeks used to infiltrate Troy, a Trojan horse is a program that does something undocumented which the programmer intended, but that the user would not approve of if he or she knew about it. According to some people, a virus is a particular case of a Trojan horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to a non-replicating malicious program.
For more information on viruses, see the virus-L/comp.virus FAQ at: http://www.faqs.org/faqs/by-newsgroup/comp/comp.virus.html
What is Netscape, and where can I get it?
Netscape is a suite of software components for sharing, accessing, and communicating information via intranets and the Internet. Most versions of Netscape include components for browsing, email, authoring HTML pages, and reading newsgroups. You can download the latest version of Netscape at:
http://browser.netscape.com/ns8/
Indiana University students, faculty, and staff can download a current version of Netscape via IUware Online at:
http://iuware.indiana.edu/
For access to earlier versions, see:
ftp://ftp.netscape.com/pub/
Netscape 8.x includes only Netscape Browser. Netscape 7.x includes the following components:
* Netscape Navigator: Netscape Navigator is the web browser in the Netscape suite of programs, although often when people speak generically of "Netscape" they mean only the browser.
* Netscape Mail: Netscape Mail is an application for sending and receiving email as well as reading Usenet newsgroups. You can use Netscape Mail to access multiple email accounts and manage all your email in one place.
* Netscape Composer: Netscape Composer is an editor that you can use to create HTML-based documents for the web. Toolbar buttons in Composer allow you to make lists or tables, add images and links to other pages, and select text colors and font styles.
* Integrated AOL Instant Messenger: This instant messaging software is compatible with the stand-alone version of AOL Instant Messenger (AIM), and allows you to communicate with anyone who uses AIM.
Earlier versions (version 4.8 and below), known collectively as Netscape Communicator, included the following components:
* Netscape Navigator (web browser)
* Netscape Messenger (Email program and newsreader)
Note: In Communicator 4.0.x, the Usenet newsreader was a separate component called Collabra.
* Netscape Composer (HTML editor and web page publisher)
http://browser.netscape.com/ns8/
Indiana University students, faculty, and staff can download a current version of Netscape via IUware Online at:
http://iuware.indiana.edu/
For access to earlier versions, see:
ftp://ftp.netscape.com/pub/
Netscape 8.x includes only Netscape Browser. Netscape 7.x includes the following components:
* Netscape Navigator: Netscape Navigator is the web browser in the Netscape suite of programs, although often when people speak generically of "Netscape" they mean only the browser.
* Netscape Mail: Netscape Mail is an application for sending and receiving email as well as reading Usenet newsgroups. You can use Netscape Mail to access multiple email accounts and manage all your email in one place.
* Netscape Composer: Netscape Composer is an editor that you can use to create HTML-based documents for the web. Toolbar buttons in Composer allow you to make lists or tables, add images and links to other pages, and select text colors and font styles.
* Integrated AOL Instant Messenger: This instant messaging software is compatible with the stand-alone version of AOL Instant Messenger (AIM), and allows you to communicate with anyone who uses AIM.
Earlier versions (version 4.8 and below), known collectively as Netscape Communicator, included the following components:
* Netscape Navigator (web browser)
* Netscape Messenger (Email program and newsreader)
Note: In Communicator 4.0.x, the Usenet newsreader was a separate component called Collabra.
* Netscape Composer (HTML editor and web page publisher)
What is a modem?
A modem allows you to send and receive information over the phone line with your computer. You could send a picture of your dog to a friend, or receive (download) a document sent to you via email.
"Modem" is an acronym that stands for "MOdulator/DEModulator". These are the technical terms for the way your modem converts information you send from your computer into sounds (the MOdulator part) which a modem on the other end of the phone line can translate back into information (the DEModulator part).
"Modem" is an acronym that stands for "MOdulator/DEModulator". These are the technical terms for the way your modem converts information you send from your computer into sounds (the MOdulator part) which a modem on the other end of the phone line can translate back into information (the DEModulator part).
What is the difference between memory and disk storage?
Memory and disk storage both refer to internal storage space in a computer.
The term memory usually means RAM (Random Access Memory). To refer to hard drive storage, the terms disk space or storage are usually used.
Typically, computers have much less memory than disk space, because RAM is much more expensive per megabyte than a hard disk. Today, a typical desktop computer might come with 512MB of RAM, and a 40 gigabyte hard disk.
Virtual memory is disk space that has been designated to act like RAM. For more information, see the Knowledge Base document What is virtual memory?
Computers also contain a small amount of ROM, or read-only memory, containing permanent or semi-permanent (firmware) instructions for checking hardware and starting up the computer. On a PC, this is called the BIOS.
The term memory usually means RAM (Random Access Memory). To refer to hard drive storage, the terms disk space or storage are usually used.
Typically, computers have much less memory than disk space, because RAM is much more expensive per megabyte than a hard disk. Today, a typical desktop computer might come with 512MB of RAM, and a 40 gigabyte hard disk.
Virtual memory is disk space that has been designated to act like RAM. For more information, see the Knowledge Base document What is virtual memory?
Computers also contain a small amount of ROM, or read-only memory, containing permanent or semi-permanent (firmware) instructions for checking hardware and starting up the computer. On a PC, this is called the BIOS.
What is linux ?
Linux, originally created by Linus Torvald, is an operating system that is freely distributed under the terms of the GNU Public License. It behaves like Unix, but does not come from the same source code base. Linux is available in both source code and binary form.
Linux offers standard Unix features such as multiuser support, multitasking, networking, and POSIX compliance. It supports all the standard Unix utilities (e.g., gcc, Emacs, the X Window System, Ghostscript, bash) and can compile most major Unix packages with little effort. DOS emulation is also available, and an X Window System-based Microsoft Windows compatibility layer is in development.
The complete Linux operating system consists of the Linux core, or kernel, combined with the utilities and applications required for a fully functional operating system. There are several such combinations, called distributions, put out by various companies, and there is no such thing as an official version. For more information on Linux, visit the Unix Systems Support Group (USSG) web site and click the link under Unix Flavors at:
http://www.ussg.iu.edu/
The Linux Documentation Project offers general guides, specific "HOWTO" documents, FAQs, and links to a wealth of other resources at:
http://www.tldp.org
Linux offers standard Unix features such as multiuser support, multitasking, networking, and POSIX compliance. It supports all the standard Unix utilities (e.g., gcc, Emacs, the X Window System, Ghostscript, bash) and can compile most major Unix packages with little effort. DOS emulation is also available, and an X Window System-based Microsoft Windows compatibility layer is in development.
The complete Linux operating system consists of the Linux core, or kernel, combined with the utilities and applications required for a fully functional operating system. There are several such combinations, called distributions, put out by various companies, and there is no such thing as an official version. For more information on Linux, visit the Unix Systems Support Group (USSG) web site and click the link under Unix Flavors at:
http://www.ussg.iu.edu/
The Linux Documentation Project offers general guides, specific "HOWTO" documents, FAQs, and links to a wealth of other resources at:
http://www.tldp.org
What is the difference between a LAN, a MAN, and a WAN, and what is a LAN connection?
A LAN (local area network) is a group of computers and network devices connected together, usually within the same building. By definition, the connections must be high-speed and relatively inexpensive (e.g., token ring or Ethernet).
A MAN (metropolitan area network) is a larger network that usually spans several buildings in the same city or town. The IUB network is an example of a MAN.
A WAN (wide area network) is, in comparison, not restricted to a geographical location, although it might be confined within the bounds of a state or a country. A WAN connects several LANs, and may be limited to an enterprise (a corporation or an organization) or accessible to the public. The technology is high-speed, and is relatively expensive. The Internet is an example of a worldwide public WAN.
A LAN connection is a high-speed connection to a LAN. On the IUB campus, most connections are either Ethernet (10Mbps) or Fast Ethernet (100Mbps), and a few locations have Gigabit Ethernet (1000Mbps) connections.
A MAN (metropolitan area network) is a larger network that usually spans several buildings in the same city or town. The IUB network is an example of a MAN.
A WAN (wide area network) is, in comparison, not restricted to a geographical location, although it might be confined within the bounds of a state or a country. A WAN connects several LANs, and may be limited to an enterprise (a corporation or an organization) or accessible to the public. The technology is high-speed, and is relatively expensive. The Internet is an example of a worldwide public WAN.
A LAN connection is a high-speed connection to a LAN. On the IUB campus, most connections are either Ethernet (10Mbps) or Fast Ethernet (100Mbps), and a few locations have Gigabit Ethernet (1000Mbps) connections.
What is a LAN (local area network)?
Local area networks (LANs) are computer networks ranging in size from a few computers in a single office to hundreds or even thousands of devices spread across several buildings. They function to link computers together and provide shared access to printers, file servers, and other services. LANs in turn may be plugged into larger networks, such as larger LANs or wide area networks (WANs), connecting many computers within an organization to each other and/or to the Internet.
Because the technologies used to build LANs are extremely diverse, it is impossible to describe them except in the most general way. Universal components consist of the physical media that connect devices, interfaces on the individual devices that connect to the media, protocols that transmit data across the network, and software that negotiates, interprets, and administers the network and its services. Many LANs also include signal repeaters and bridges or routers, especially if they are large or connect to other networks.
The level of management required to run a LAN depends on the type, configuration, and number of devices involved, but in some cases it can be considerable.
Forums for LAN discussion include newsgroups in the comp.dcom.lans.* hierarchy.
Because the technologies used to build LANs are extremely diverse, it is impossible to describe them except in the most general way. Universal components consist of the physical media that connect devices, interfaces on the individual devices that connect to the media, protocols that transmit data across the network, and software that negotiates, interprets, and administers the network and its services. Many LANs also include signal repeaters and bridges or routers, especially if they are large or connect to other networks.
The level of management required to run a LAN depends on the type, configuration, and number of devices involved, but in some cases it can be considerable.
Forums for LAN discussion include newsgroups in the comp.dcom.lans.* hierarchy.
What is the JPEG graphics file format?
JPEG (pronounced "jay-peg") is a standardized image compression mechanism. JPEG stands for Joint Photographic Experts Group, the original name of the committee that wrote the standard. JPEG compresses either full-color or grayscale images and works best with photographs and artwork.
JPEG uses a lossy compression method, meaning that the decompressed image isn't quite the same as the one you started with. (There are lossless image compression algorithms, but JPEG achieves much greater compression than is possible with lossless methods.) This method fools the eye by using the fact that people perceive small color changes less accurately than small changes in brightness.
JPEG was developed for two reasons: it makes image files smaller and it stores 24-bit per pixel color data (full color) instead of 8-bit per pixel data. Making image files smaller is important for storing and transmitting files. Being able to compress a 2MB full-color file down to, for example, 100KB makes a big difference in disk space and transmission time. JPEG can easily provide 20:1 compression of full-color data. (With GIF images, the size ratio is usually more like 4:1.)
This information is based on the JPEG FAQ, which is available at:
http://www.faqs.org/faqs/jpeg-faq/
JPEG uses a lossy compression method, meaning that the decompressed image isn't quite the same as the one you started with. (There are lossless image compression algorithms, but JPEG achieves much greater compression than is possible with lossless methods.) This method fools the eye by using the fact that people perceive small color changes less accurately than small changes in brightness.
JPEG was developed for two reasons: it makes image files smaller and it stores 24-bit per pixel color data (full color) instead of 8-bit per pixel data. Making image files smaller is important for storing and transmitting files. Being able to compress a 2MB full-color file down to, for example, 100KB makes a big difference in disk space and transmission time. JPEG can easily provide 20:1 compression of full-color data. (With GIF images, the size ratio is usually more like 4:1.)
This information is based on the JPEG FAQ, which is available at:
http://www.faqs.org/faqs/jpeg-faq/
What is Java?
Java is a portable object-oriented language developed by Sun Microsystems. Originally used mostly for web programming, it is now used primarily to develop large web-based applications.
For more information about Java, see the Java home page at:
http://java.sun.com/
For links to information about specific topics, consult the Google directory's Java section at:
http://directory.google.com/Top/Computers/Programming/Languages/Java/
For more information about Java, see the Java home page at:
http://java.sun.com/
For links to information about specific topics, consult the Google directory's Java section at:
http://directory.google.com/Top/Computers/Programming/Languages/Java/
What is iTunes and what does it do?
In January 2001, Apple introduced iTunes, an all-in-one music playing application for Mac OS 9.0.4 and later and Mac OS X. In October 2003, Apple released iTunes for Windows 2000 and XP. You can do a number of things with iTunes, some of which are described below:
* Listen to CDs: iTunes will play your music CDs. You can shuffle and repeat your favorite tracks, just like a regular CD player.
* Buy music online: With the iTunes Music Store, you may purchase songs, albums, and audiobooks that you can play on up to five computers, burn to CD, or export to an iPod.
* Import music from your CDs: iTunes will also import or rip music from your CDs. You can import in AAC (the codec underlying MP4), MP3, AIFF, WAV, or Apple Lossless Encoder formats. The music will then be stored on your hard drive for easy access anytime.
Note: UITS does not condone the importing or trading of music from CDs which you do not personally own. To do so is a violation of the United States copyright law.
* Create your own playlists: Once you have stored your music on your hard drive, you can play it in any order you like by creating a playlist. Searching your music library is easy because iTunes will search your library as you type. Just type a few letters and you will find the song you are looking for. You can organize your music by artist, album, or song.
* Burn CDs or DVDs: iTunes can burn your files to a CD or DVD. Once you have created your playlists, you can create your own CD with a CD-RW drive, or DVD with a DVD-R drive. This used to work only with Apple's internal drives, but the most recent versions of iTunes support some external CD-RW and DVD-R drives. Consult Apple's and the manufacturer's documentation to see if your drive is supported.
* Synchronize with your iPod: Plug in your iPod, and iTunes will synchronize automatically, at high speeds over FireWire or USB 2.0.
* Export to a non-Apple MP3 player: You can export your playlists through USB or USB 2.0 to a non-Apple commercial MP3 player to take with you wherever you go. Simply drag your files to the MP3 player's icon and the files will be uploaded.
* Listen to Internet Radio: iTunes features a built-in Internet Radio Tuner which will find Internet Radio Stations by genre. Browse through the available stations, and select the one you want.
* Listen to Podcasts: Subscribe to free radio shows and audio programs, and the latest episodes will sync to your iPod automatically each time you dock it.
* Visualize your music: Apple has included a music visualizer that plays a light show along with the music.
* Play movie trailers: You can view movie trailers available on Apple's web site through iTunes. Access this option either through the iTunes Music Store from within iTunes, or by selecting the Watch Trailers in iTunes 5 Now option on Apple's Movie Trailers page at: http://www.apple.com/trailers/
* Transcode music to a different format: After you have imported your music files into iTunes, you can transcode them to a different format (e.g., MP3 to AAC or WAV to MP3).
* Listen to music shared across the network: You can choose to make your playlists available to other iTunes users on your local network, and you can likewise access others' iTunes playlists. The available playlists appear in iTunes automatically.
* Listen to CDs: iTunes will play your music CDs. You can shuffle and repeat your favorite tracks, just like a regular CD player.
* Buy music online: With the iTunes Music Store, you may purchase songs, albums, and audiobooks that you can play on up to five computers, burn to CD, or export to an iPod.
* Import music from your CDs: iTunes will also import or rip music from your CDs. You can import in AAC (the codec underlying MP4), MP3, AIFF, WAV, or Apple Lossless Encoder formats. The music will then be stored on your hard drive for easy access anytime.
Note: UITS does not condone the importing or trading of music from CDs which you do not personally own. To do so is a violation of the United States copyright law.
* Create your own playlists: Once you have stored your music on your hard drive, you can play it in any order you like by creating a playlist. Searching your music library is easy because iTunes will search your library as you type. Just type a few letters and you will find the song you are looking for. You can organize your music by artist, album, or song.
* Burn CDs or DVDs: iTunes can burn your files to a CD or DVD. Once you have created your playlists, you can create your own CD with a CD-RW drive, or DVD with a DVD-R drive. This used to work only with Apple's internal drives, but the most recent versions of iTunes support some external CD-RW and DVD-R drives. Consult Apple's and the manufacturer's documentation to see if your drive is supported.
* Synchronize with your iPod: Plug in your iPod, and iTunes will synchronize automatically, at high speeds over FireWire or USB 2.0.
* Export to a non-Apple MP3 player: You can export your playlists through USB or USB 2.0 to a non-Apple commercial MP3 player to take with you wherever you go. Simply drag your files to the MP3 player's icon and the files will be uploaded.
* Listen to Internet Radio: iTunes features a built-in Internet Radio Tuner which will find Internet Radio Stations by genre. Browse through the available stations, and select the one you want.
* Listen to Podcasts: Subscribe to free radio shows and audio programs, and the latest episodes will sync to your iPod automatically each time you dock it.
* Visualize your music: Apple has included a music visualizer that plays a light show along with the music.
* Play movie trailers: You can view movie trailers available on Apple's web site through iTunes. Access this option either through the iTunes Music Store from within iTunes, or by selecting the Watch Trailers in iTunes 5 Now option on Apple's Movie Trailers page at: http://www.apple.com/trailers/
* Transcode music to a different format: After you have imported your music files into iTunes, you can transcode them to a different format (e.g., MP3 to AAC or WAV to MP3).
* Listen to music shared across the network: You can choose to make your playlists available to other iTunes users on your local network, and you can likewise access others' iTunes playlists. The available playlists appear in iTunes automatically.
What should I do if someone else has been trying to log into my account?
Unfortunately, it is extremely difficult for UITS to know who is trying to access your account if the individual responsible is using your username and password. However, as long as you keep your password secret and change it frequently, your account should be safe.
Many people report security breaches to the Support Center erroneously, often due to a misunderstanding regarding the recorded time of their most recent login. This can be due to a system's use of the 24-hour clock, or even Greenwich Mean Time (GMT) instead of Eastern Standard Time (EST).
On the other hand, you might see something like: Last unsuccessful login for dvader: Fri Dec 14 12:35:24 2004 on ttyq1 The word "unsuccessful" means that someone has attempted to use your username to log in, but used the wrong password. In combination with the time of the "Last successful login" message, you may be able to determine whether someone succeeded in guessing your password.
Sometimes people make typing mistakes, maybe adding or omitting a letter in their usernames when logging in. For example, jxsmith might erroneously enter jsmith when prompted for a username. The next time the real user jsmith attempts to log in, it will appear that someone has attempted to log into that account. In this case, jxsmith was not attempting malicious or illegal behavior, but rather is guilty of simple human error.
If you suspect that someone has guessed your password and logged into your account:
1. Change your password immediately.
2. Then, report the following information to it-incident@iu.edu :
* Which account(s) you believe was/were broken into, including your username and system, e.g., dvader on Steel
* The time(s) that you believe your account was compromised
* Why you think your account was compromised
Note: Do not include any names of individuals you suspect may have accessed your account(s). The Information Technology Security Office (ITSO) at IU will request this information if it is needed.
For maximum security, please change your password frequently. Also, remember that it is against IU policy to share your password or accounts with others
What are hackers and crackers?
Originally, the term "hacker" described any amateur computer programmer who discovered ways to make software run more efficiently. In a broader sense, hacker describes anyone who writes computer programs, modifies computer hardware, or tinkers with computers or electronic devices for fun. Hackers will "hack" on a problem until they find a solution, always trying to make their equipment work in new, more efficient ways.
The popular definition of hacker has changed to describe a person who maliciously breaks into computer networks with the intent to snoop, steal data, or tamper with files.
Legitimate hackers resent the association of the term hacker with criminal activity. They use the term "cracker" to describe someone who breaks into networks.
The popular definition of hacker has changed to describe a person who maliciously breaks into computer networks with the intent to snoop, steal data, or tamper with files.
Legitimate hackers resent the association of the term hacker with criminal activity. They use the term "cracker" to describe someone who breaks into networks.
What is a byte, and what are the other units of measure for digital information?
A byte is a unit of measure for digital information. A single byte contains eight consecutive bits, and is capable of storing a single ASCII character, like "h".
A kilobyte (KB) is 1,024 bytes, not one thousand bytes as might be expected. This odd number results from the fact that computers use binary (base two) math, instead of a decimal (base ten) system.
Computer storage and memory is often measured in megabytes (MB). A medium-sized novel contains about 1MB of information. 1MB is 1,024 kilobytes, or 1,048,576 (1024x1024) bytes, not one million bytes. Again, this number results from the fact that computers use binary math.
Similarly, one gigabyte (GB) is 1,024MB, or 1,073,741,824 (1024x1024x1024) bytes. A terabyte (TB) is 1,024GB; 1TB is about the same amount of information as all of the books in a large library, or roughly 1,610 CDs worth of data. A petabyte (PB) is 1,024TB. Indiana University is now building storage systems capable of holding petabytes of data. An exabyte (EB) is 1,024PB. A zettabyte (ZB) is 1,024EB. And finally, a yottabyte (YB) 1,024ZB.
A kilobyte (KB) is 1,024 bytes, not one thousand bytes as might be expected. This odd number results from the fact that computers use binary (base two) math, instead of a decimal (base ten) system.
Computer storage and memory is often measured in megabytes (MB). A medium-sized novel contains about 1MB of information. 1MB is 1,024 kilobytes, or 1,048,576 (1024x1024) bytes, not one million bytes. Again, this number results from the fact that computers use binary math.
Similarly, one gigabyte (GB) is 1,024MB, or 1,073,741,824 (1024x1024x1024) bytes. A terabyte (TB) is 1,024GB; 1TB is about the same amount of information as all of the books in a large library, or roughly 1,610 CDs worth of data. A petabyte (PB) is 1,024TB. Indiana University is now building storage systems capable of holding petabytes of data. An exabyte (EB) is 1,024PB. A zettabyte (ZB) is 1,024EB. And finally, a yottabyte (YB) 1,024ZB.
What is Mozilla Firefox and where can I get it?
What is Mozilla Firefox and where can I get it?
Developed by Mozilla, Firefox is a free, open-source, web browser for Windows, Linux, and Mac OS X. You can download the latest version at:
http://www.mozilla.com/firefox/
For Indiana University students, faculty, and staff, Firefox is also available via IUWare Online:
http://iuware.iu.edu/
For more information about Firefox and the Mozilla Foundation, visit:
http://www.mozilla.org/
Developed by Mozilla, Firefox is a free, open-source, web browser for Windows, Linux, and Mac OS X. You can download the latest version at:
http://www.mozilla.com/firefox/
For Indiana University students, faculty, and staff, Firefox is also available via IUWare Online:
http://iuware.iu.edu/
For more information about Firefox and the Mozilla Foundation, visit:
http://www.mozilla.org/
What isURL ?
What is a URL?
URL stands for Uniform Resource Locator, and is used to specify addresses on the World Wide Web. A URL is the fundamental network identification for any resource connected to the web (e.g., hypertext pages, images, and sound files).
URLs have the following format:
protocol://hostname/other_information
For example, the URL for Indiana University's home page is:
http://www.indiana.edu/
The protocol specifies how information from the link is transferred. The protocol used for web resources is HyperText Transfer Protocol (HTTP). Other protocols compatible with most web browsers include FTP, telnet, newsgroups, and Gopher. The protocol is followed by a colon, two slashes, and then the domain name. The domain name is the computer on which the resource is located. Links to particular files or subdirectories may be further specified after the domain name. The directory names are separated by single forward slashes.
You can find additional information about URLs at the World Wide Web Consortium's (W3C) Naming and Addressing page at:
http://www.w3.org/Addressing/
URL stands for Uniform Resource Locator, and is used to specify addresses on the World Wide Web. A URL is the fundamental network identification for any resource connected to the web (e.g., hypertext pages, images, and sound files).
URLs have the following format:
protocol://hostname/other_information
For example, the URL for Indiana University's home page is:
http://www.indiana.edu/
The protocol specifies how information from the link is transferred. The protocol used for web resources is HyperText Transfer Protocol (HTTP). Other protocols compatible with most web browsers include FTP, telnet, newsgroups, and Gopher. The protocol is followed by a colon, two slashes, and then the domain name. The domain name is the computer on which the resource is located. Links to particular files or subdirectories may be further specified after the domain name. The directory names are separated by single forward slashes.
You can find additional information about URLs at the World Wide Web Consortium's (W3C) Naming and Addressing page at:
http://www.w3.org/Addressing/
What is HTML, and where can I find a guide for creating HTML documents?
What is HTML, and where can I find a guide for creating HTML documents?
HyperText Markup Language (HTML) is the formatting language for a hypertext or hypermedia document, viewable with a web browser such as Netscape, Firefox, Safari, Internet Explorer, or Lynx. HTML documents are plain ASCII text and can be created with a text editor, but they contain formatting codes and links to other documents and media (including images and sounds) which can be followed using the web browser.
For help getting started with HTML, see webmonkey's "Authoring: HTML Basics" page at:
http://webmonkey.com/webmonkey/authoring/html_basics/index.html
For a complete index of all HTML elements and attributes, see the following pages from the World Wide Web Consortium (W3C):
http://www.w3.org/TR/REC-html40/index/elements.html http://www.w3.org/TR/REC-html40/index/attributes.html
For Indiana University-specific information and help, see the IU Webmaster web page at:
http://www.indiana.edu/~wmhome/
HyperText Markup Language (HTML) is the formatting language for a hypertext or hypermedia document, viewable with a web browser such as Netscape, Firefox, Safari, Internet Explorer, or Lynx. HTML documents are plain ASCII text and can be created with a text editor, but they contain formatting codes and links to other documents and media (including images and sounds) which can be followed using the web browser.
For help getting started with HTML, see webmonkey's "Authoring: HTML Basics" page at:
http://webmonkey.com/webmonkey/authoring/html_basics/index.html
For a complete index of all HTML elements and attributes, see the following pages from the World Wide Web Consortium (W3C):
http://www.w3.org/TR/REC-html40/index/elements.html http://www.w3.org/TR/REC-html40/index/attributes.html
For Indiana University-specific information and help, see the IU Webmaster web page at:
http://www.indiana.edu/~wmhome/
What is domain names ?
Domain names are the word sequences users enter in their address bar of an internet navigator to visit a specific web site. Each domain name is assigned to an IP address. The DNS ( Domain Name System ) is used to translate the IP addresses into words.
What is Digital Camera ?
A type of camera that uses a disk instead of film. Used because it provides immediate photos on an LCD screen, and because it reduces the need for film and developing, however, digital cameras are not always reliable in producing evidence of hauntings. Because of the lack of film, there are no negatives to compare the photo to. In addition, uncolored pixels can give the appearance of orbs. A 35 mm camera with 400 speed film works just as well and is easy to use. The small cost of developing is well worth it when you see the finished product.
What is computer ?
A computer is a device or machine for making calculations or controlling operations that are expressible in numerical or logical terms. Computers are made from components that perform simple well-defined functions. The complex interactions of these components endow computers with the ability to process information. If correctly configured (usually by programming) a computer can be made to represent some aspect of a problem or part of a system. ...
What is Multimedia?
What is Multimedia?
The word "Multimedia" simply means being able to communicate in more than one way. This means that, whether you are aware of it or not, you already give multimedia presentations. For example if you rub your temples while telling someone you have a headache or when you point to a diagram on a board whilst speaking to a class of students you are using multimedia to get your point across. In this instance your are using movement in conjunction with sound. Check out the examples at the bottom of the page.
So multimedia is all about communicating in several ways.
For example the computer you are using to view this material is capable of flashing text and beeping when there is a problem. It is already a multimedia computer - anything else is a matter of degree. In other words the more capable your computer is at handling sound, video and graphics the better your multimedia packages will look.
Originally the term multimedia was used by institutions who run distance learning courses in which they deliver content via a combination of text, TV, telephone, audio cassette and the radio. So the idea of using multimedia for education is not new. What is new is the way in which we now use computers to bring these things together. The advent of high resolution screens and sound and video playback facilities for computers has resulted in the increased use of multimedia applications for education.
A typical multimedia application is charactorised by the following features:
* the different media it possesses and makes use of
* the use of digital technology
* the interaction it demands of the user
* and the integration of sound, images, text and data into seamless applications
The word "Multimedia" simply means being able to communicate in more than one way. This means that, whether you are aware of it or not, you already give multimedia presentations. For example if you rub your temples while telling someone you have a headache or when you point to a diagram on a board whilst speaking to a class of students you are using multimedia to get your point across. In this instance your are using movement in conjunction with sound. Check out the examples at the bottom of the page.
So multimedia is all about communicating in several ways.
For example the computer you are using to view this material is capable of flashing text and beeping when there is a problem. It is already a multimedia computer - anything else is a matter of degree. In other words the more capable your computer is at handling sound, video and graphics the better your multimedia packages will look.
Originally the term multimedia was used by institutions who run distance learning courses in which they deliver content via a combination of text, TV, telephone, audio cassette and the radio. So the idea of using multimedia for education is not new. What is new is the way in which we now use computers to bring these things together. The advent of high resolution screens and sound and video playback facilities for computers has resulted in the increased use of multimedia applications for education.
A typical multimedia application is charactorised by the following features:
* the different media it possesses and makes use of
* the use of digital technology
* the interaction it demands of the user
* and the integration of sound, images, text and data into seamless applications
What is a mobile phone ?
A mobile or cellular telephone is a long-range, portable electronic device for personal telecommunications over long distances.
Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception are satellite phones). Cellular networks were first introduced in the early to mid 1980s (the 1G generation). Prior mobile phones operating without a cellular network (the so-called 0G generation), such as Mobile Telephone Service, date back to 1945. Until the mid to late 1980s, most mobile phones were sufficiently large that they were permanently installed in vehicles as car phones. With the advance of miniaturization, currently the vast majority of mobile phones are handheld. In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video.
The world's largest mobile phone manufacturers include Audiovox, BenQ-Siemens, High Tech Computer Corporation, Fujitsu, Kyocera, LG, Motorola, NEC,[i-mate], Nokia, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Sagem, Samsung, Sanyo, Sharp, Siemens SK Teletech, Sony Ericsson, T&A Alcatel, T-Mobile, and Toshiba.
Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception are satellite phones). Cellular networks were first introduced in the early to mid 1980s (the 1G generation). Prior mobile phones operating without a cellular network (the so-called 0G generation), such as Mobile Telephone Service, date back to 1945. Until the mid to late 1980s, most mobile phones were sufficiently large that they were permanently installed in vehicles as car phones. With the advance of miniaturization, currently the vast majority of mobile phones are handheld. In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video.
The world's largest mobile phone manufacturers include Audiovox, BenQ-Siemens, High Tech Computer Corporation, Fujitsu, Kyocera, LG, Motorola, NEC,[i-mate], Nokia, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Sagem, Samsung, Sanyo, Sharp, Siemens SK Teletech, Sony Ericsson, T&A Alcatel, T-Mobile, and Toshiba.
What is a mp3 player ?
A digital audio player (DAP) is a device that stores, organizes and plays digital music files. It is more commonly referred to as an MP3 player (because of that format's ubiquity), but DAPs often play many additional file formats. Some formats are proprietary, such as Windows Media Audio (WMA), and, to a degree, Advanced Audio Coding (AAC) and MP3. Some of these formats also may incorporate restrictive digital rights management (DRM) technology, such as WMA DRM and Apple's "FairPlay", which are often part of certain paid download sites. Other formats are completely patent-free or otherwise open, such as Ogg Vorbis, FLAC, Speex (all part of the Ogg open multimedia project), and Module file formats.
There are three main types of digital audio players:
* MP3 CD Players - Devices that play CDs. Often, they can be used to play both audio CDs and homemade data CDs containing MP3 or other digital audio files.
* Flash-based Players - These are solid state devices that hold digital audio files on internal or external media, such as memory cards. Due to technological limitations, these are relatively low-storage devices, commercially ranging from 128MB to 8GB, such as the 2nd generation Ipod Nano, which can often be extended with additional memory. As they are solid state and do not have moving parts, they are very resilient. In effect, they do not suffer limitations that owners of Hard Drive-based players face, such as fears of dropping their player or fragmentation. Such players are generally integrated into USB keydrives.
* Hard Drive-based Players or Digital Jukeboxes - Devices that read digital audio files from a hard drive. These players have higher capacities, ranging from 1.5GB to 100GB, depending on the hard drive technology. At typical encoding rates, this means that thousands of songs — perhaps an entire music collection — can be stored in one MP3 player. Due to their capacity and physical size, image and video media support is becoming standard among Hard Drive-based players. The Apple iPod and Creative Zen are examples of popular digital jukeboxes.
There are three main types of digital audio players:
* MP3 CD Players - Devices that play CDs. Often, they can be used to play both audio CDs and homemade data CDs containing MP3 or other digital audio files.
* Flash-based Players - These are solid state devices that hold digital audio files on internal or external media, such as memory cards. Due to technological limitations, these are relatively low-storage devices, commercially ranging from 128MB to 8GB, such as the 2nd generation Ipod Nano, which can often be extended with additional memory. As they are solid state and do not have moving parts, they are very resilient. In effect, they do not suffer limitations that owners of Hard Drive-based players face, such as fears of dropping their player or fragmentation. Such players are generally integrated into USB keydrives.
* Hard Drive-based Players or Digital Jukeboxes - Devices that read digital audio files from a hard drive. These players have higher capacities, ranging from 1.5GB to 100GB, depending on the hard drive technology. At typical encoding rates, this means that thousands of songs — perhaps an entire music collection — can be stored in one MP3 player. Due to their capacity and physical size, image and video media support is becoming standard among Hard Drive-based players. The Apple iPod and Creative Zen are examples of popular digital jukeboxes.
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