A listserv is an automated mailing list. When an e-mail message is sent to a listserv, it is automatically sent to all list subscribers.

Microsoft Access, often abbreviated "MS Access," is a popular database application for Windows. Access allows users to create custom databases that store information in an organized structure. The program also provides a visual interface for creating custom forms, tables, and SQL queries. Data can be entered into an Access database using either visual forms or a basic spreadsheet interface. The information stored within an Access database can be browsed, searched, and accessed from other programs, including Web services.

While Access is a proprietary database management system (DBMS), it is compatible with other database programs since it supports Open Database Connectivity (ODBC). This allows data to be sent to and from other database programs, such as MS SQL, FoxPro, Filemaker Pro, and Oracle databases. This compatibility also enables Access to serve as the back end for a database-driven website. In fact, Microsoft FrontPage and Expression Web, as well as ASP.NET have built-in support for Access databases. For this reason, websites hosted on Microsoft Windows servers often use Access databases for generating dynamic content.

Stands for "Access Control List." An ACL is a list of user permissions for a file, folder, or other object. It defines what users and groups can access the object and what operations they can perform. These operations typically include read, write, and execute. For example, if an ACL specifies read-only access for a specific user of a file, that user will be able open the file, but cannot write to it or run the file.

Access control lists provide a straightforward method of managing file and folder permissions. They are used by most operating systems, including Windows, Mac, and Unix systems. While ACLs are typically hidden from the user, they can often be modified using a graphical interface. For example, in Mac OS X 10.5, ACL settings can be edited by selecting a file or folder and choosing "Get Info." The access control settings can be modified within the "Sharing and Permissions" section of the window. On Unix systems, ACLs can be edited using the chmod() command.

Active-matrix technology is used in high-quality flat-panel displays, such as laptop screens and thin computer monitors. The images on active matrix screens are created by laying diodes, or small semiconductors, over a grid of ultra-small wires. When a current passes through the diodes, they light up in different colors, depending on the strength of the current. Thousands of these diodes next to each other form an image on the screen.

To keep the diodes in an on or off state, active-matrix displays use transistors, which are not found in the lower-quality passive-matrix displays. The transistors help make the active-matrix displays brighter and give them more contrast than passive-matrix displays.

This Microsoft-based technology was built to link desktop applications to the World Wide Web. Using ActiveX development tools, software developers can create interactive Web content for their applications. For example, Word and Excel documents can be viewed directly in Web browsers that supports ActiveX. While ActiveX is a useful technology, the downside is that you need to have a up-to-date version ActiveX installed on your machine in order to use ActiveX-enabled content.

"Ad Hoc" is actually a Latin phrase that means "for this purpose." It is often used to describe solutions that are developed on-the-fly for a specific purpose. In computer networking, an ad hoc network refers to a network connection established for a single session and does not require a router or a wireless base station.

For example, if you need to transfer a file to your friend's laptop, you might create an ad hoc network between your computer and his laptop to transfer the file. This may be done using an Ethernet crossover cable, or the computers' wireless cards to communicate with each other. If you need to share files with more than one computer, you could set up a mutli-hop ad hoc network, which can transfer data over multiple nodes.

Basically, an ad hoc network is a temporary network connection created for a specific purpose (such as transferring data from one computer to another). If the network is set up for a longer period of time, it is just a plain old local area network (LAN).

Adware is free software that is supported by advertisements. Common adware programs are toolbars that sit on your desktop or work in conjunction with your Web browser. They include features like advanced searching of the Web or your hard drive and better organization of your bookmarks and shortcuts. Adware can also be more advanced programs such as games or utilities. They are free to use, but require you to watch advertisements as long as the programs are open. Since the ads often allow you to click to a Web site, adware typically requires an active Internet connection to run.

Most adware is safe to use, but some can serve as spyware, gathering information about you from your hard drive, the Web sites you visit, or your keystrokes. Spyware programs can then send the information over the Internet to another computer. So be careful what adware you install on your computer. Make sure it is from a reputable company and read the privacy agreement that comes with it.

Stands for "Automatic Document Feeder." An ADF is used in copiers and scanners to feed pages into the machine. It allows multiple pages to be copied or scanned at one time without the need to place each individual page in the copier or scanner.

A flatbed scanner, on the other hand, requires each page to be individually placed on the scanning surface. While this is convenient for single pages, copying 80 pages would require a lot of manual page-loading! Some copy machines include both an automatic document feeder and a flatbed scanning surface so that either method can be used.

Stands for "Digital Versatile Disc Recordable." A DVD-R looks the same as a regular DVD, but like a CD-R, it can be used to record data. Once a DVD-R has been "burned," or written to, it cannot be written to again. A basic single-sided, single-layer DVD-R disc can store 4.7GB of data. Double-layer discs can store 8.5GB, while double-sided DVD-Rs can store 9.4GB.

DVD-R is the most common format of writable DVDs (compared to the DVD+R and DVD-RAM formats). Most DVD players and DVD-ROM drives can read DVD-R discs. That means you can use a DVD-R disc to back up several gigabytes of data on your computer or make your own video DVD. The Apple SuperDrive used in many Macintosh computers supports the DVD-R format.

Stands for "Asymmetric Digital Subscriber Line." ADSL is a type of DSL, which is a method of transferring data over copper telephone lines. While symmetrical DSL (SDSL) uploads and downloads data at the same speed, ADSL has different maximum data transfer rates for uploading and downloading data.

For example, an ADSL connection may allow download rates of 1.5Mbps, while upload speeds may only reach 256Kbps. Since most users download much more data than they upload, this difference usually does not make a noticeable impact on Internet access speeds. However, for Web servers or other computers that send a lot of data upstream, ADSL would be an inefficient choice.

Stands for "Accelerated Graphics Port." This is a graphics card expansion port designed by Intel that resides on the motherboard of a computer. PCI graphics ports typically run at 33 MHz and have a maximum transfer rate of 132 MB/sec. AGP ports, on the other hand, run at 66 MHz and can transfer data up to 528 MB/sec. This allows games and applications to store and retrieve larger, more realistic 3D shapes and textures without slowing down the animation on the screen. Additionally, AGP cards can store graphics in system memory rather than video memory, which also helps improve performance. Becuase of these advantages, AGP cards will typically have better performance per MB of VRAM than PCI graphics cards.

Stands for "Audio Interchange File Format." AIFF is an audio format originally developed by Apple Computer for storing high-quality sampled audio data. AIFF files are similar to Windows WAVE files in both size and quality. Both AIFF and WAVE files can hold CD quality audio and therefore can be burned onto an audio CD. Though the AIFF format was created by Apple, audio programs on both the Mac and PC can typically read the files.

An alert box, sometimes called a message box, is a small window that pops up on your screen to warn you that your computer is about to perform an operation with potentially damaging consequences. For example, when you choose to empty the Trash or Recycle Bin on your computer, an alert box may pop up, saying "Are you sure you want to permanently remove these items?" You are then given the choice to select "OK," to delete the items, or "Cancel," to prevent the items from being removed.

Alert boxes act as a safeguard for users, preventing us from doing things we wish we hadn't. Perhaps the most common alert box is the one that pops up when you try to close a document without saving it. You'll mostly likely see an alert box with the message, "Save changes to this document before closing?" You can select "Don't Save," to discard the changes, "Save," to save the changes before closing the document, or "Cancel," to cancel closing the document and continue working on it.

Most alert boxes include the standard alert icon -- a triangle with an exclamation point in the middle -- to get your attention. However, not all alert boxes have multiple options, such as "Cancel" and "OK." For example, an alert box may show up on your screen saying a program performed an illegal operation and has unexpectedly quit. When that happens, your only option is to select "OK" and then kick your computer for quitting the program before you had a chance to save your work.

As humans, we perceive the world in analog. Everything we see and hear is a continuous transmission of information to our senses. This continuous stream is what defines analog data. Digital information, on the other hand, estimates analog data using only ones and zeros.

For example, a turntable (or record player) is an analog device, while a CD player is digital. This is because a turntable reads bumps and grooves from a record as a continuous signal, while a CD player only reads a series of ones and zeros. Likewise, a VCR is an analog device, while a DVD player is digital. A VCR reads audio and video from a tape as a continuous stream of information, while a DVD player just reads ones and zeros from a disc.

Since digital devices read only ones and zeros, they can only approximate an audio or video signal. This means analog data is actually more accurate than digital data. However, digital data can can be manipulated easier and preserved better than analog data. More importantly, computers can only handle digital data, which is why most information today is stored digitally. But if you want to transfer video from old analog video tapes into your computer so you can edit them, you're not out of luck. You can use a digital to analog converter (DAC) to convert the analog information into a digital signal that can be recognized by your computer.

Stands for "American National Standards Institute." ANSI's primary goal is to enhance the global competitiveness of U.S. businesses and to improve the American quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems. "Voluntary" standards are driven by marketplace needs rather than regulated by the government. "Conformity assessment systems" test the compliance of a product or service to a standard. ANSI does not itself develop standards or conduct tests, rather it facilitates this work by "accrediting" (i.e., recognizing) qualified groups with appropriate expertise. The Institute is the official U.S. representative to the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). ANSI is a private, nonprofit membership organization with offices in Washington, DC and New York City.

Stands for "Application Program Interface," though it is sometimes referred to as an "Application Programming Interface." An API is a set of commands, functions, and protocols which programmers can use when building software for a specific operating system. The API allows programmers to use predefined functions to interact with the operating system, instead of writing them from scratch.

All computer operating systems, such as Windows, Unix, and the Mac OS, provide an application program interface for programmers. APIs are also used by video game consoles and other hardware devices that can run software programs. While the API makes the programmer's job easier, it also benefits the end user, since it ensures all programs using the same API will have a similar user interface.

The reason this term is in the glossary is because way too many people confuse "Apple" with "Macintosh." Apple is the company that makes Macintosh computers -- not the other way around. Apple's product line includes Power Macs, PowerBooks, iMacs, iBooks, and the popular hard drive-based MP3 player, the iPod. Apple also develops a large number of software programs, such as iTunes, iPhoto, iMovie, and iDVD. Notice a pattern here?

Though most of Apple's product names now start with the letter "i", the company has a history of creative innovation. Though Apple has less than ten percent of the marketshare in the computer business, the company still manages to lead the industry in new directions.

An application, or application program, is a software program that runs on your computer. Web browsers, e-mail programs, word processors, games, and utilities are all applications. The word "application" is used because each program has a specific application for the user. For example, a word processor can help a student create a research paper, while a video game can prevent that same student from getting the paper done.

In contrast, system software consists of programs that run in the background, enabling applications to run. These programs include assemblers, compilers, file management tools, and the operating system itself. Applications are said to run on top of the system software, since the system software is made of of "low-level" programs. While system software is automatically installed with the operating system, you can choose which applications you want to install and run on your computer.

Stands for "American Standard Code for Information Interchange." ASCII is the universal standard for the numerical codes computers use to represent all upper and lower-case letters, numbers, and puctuation. Without ASCII, each type of computer would use a different way of representing letters and numbers, causing major chaos for computer programmers (allowing them even less sleep than they already get).

ASCII makes is possible for text to be represented the same way on a Dell Dimension in Minneapolis, Minnesota as it is on an Apple Power Mac in Paris, France. There are 128 standard ASCII codes, each of which can be represented by a 7 digit binary number (because 2^7 = 128).

Just like the human backbone carries signals to many smaller nerves in the body, a network backbone carries data to smaller lines of transmission. A local backbone refers to the main network lines that connect several local area networks (LANs) together. The result is a wide area network (WAN) linked by a backbone connection.

The Internet, which is the ultimate wide area network, relies on a backbone to carry data over long distances. The Internet backbone consists of several ultra-high bandwidth connections that link together many different nodes around the world. These nodes route incoming data to smaller networks in the local region. The fewer "hops" your data needs to make before reaching the backbone, the faster it will get sent to the destination. This is why many Web hosts and ISPs have direct connections to the Internet backbone.

Backup is the most important computer term you should know.

A backup is a copy of one or more files created as an alternate in case the original data is lost or becomes unusable. For example, you may save several copies of a research paper on your hard drive as backup files incase you decide to use a previous revision. Better yet, you could save the backups to a USB flash disk, which would also protect the files if the hard drive failed.

Hard drives are meant to run for many years without crashing. But just like all electronic devices, they are not immune to problems. Because they are not solid state devices, hard drives rely on moving parts to access data, which can malfunction and cause your data to become unrecoverable. If you need proof of how fragile hard drives really are, go to your local computer store and have someone show you an open hard drive. When you realize all your data is stored in such a small, delicate device, you may have a new understanding of why you need to backup your data.

But it's not just hardware malfunctions you have to worry about. Software corruption can also damage your files. Directory structures can become damaged and cause entire folders to disappear. Files can be mistakenly deleted or corrupted by viruses or other software attacks. Program installation conflicts can make applications or files unusable. There are unfortunately many ways for your data to become damaged or disappear.

That is why it is so important to backup your data. Most people don't realize the importance of having a backup until it is too late. Of course, when you have lost years of photos, school papers, business documents, e-mail archives, music, movies, or any other data that you cannot recover, the importance of having a backup becomes all too real.

So how do you backup your data? The best way is to use an external storage device, such as an external hard drive, flash memory device, or even another computer. You can also create permanent backups using optical media, such as CD-R and DVD-R discs. Backing up individual folders and files is as easy copying them from the source media (your computer's hard disk) to the destination (an external hard drive). If you want to backup your entire system or would like to have regular backups automatically performed, you can use backup software that will backup your data for you. Many programs are available for both Mac and Windows that provide automatic backups and system restore capabilities.

If you have not yet backed up your hard drive, now is a good time to do so. It's much better to back up your data now than once it is too late.

Bandwidth refers to how much data you can send through a network or modem connection. It is usually measured in bits per second, or "bps." You can think of bandwidth as a highway with cars travelling on it. The highway is the network connection and the cars are the data. The wider the highway, the more cars can travel on it at one time. Therefore more cars can get to their destinations faster. The same principle applies to computer data -- the more bandwidth, the more information that can be transferred within a given amount of time.

Whether you like it or not, much of the Web is run by advertising. Just like television or radio, websites can offer free content by generating revenue from advertising. While you may get tired of Web ads from time to time, most people would agree that seeing a few advertisements here and there is better than paying a usage fee for each website.

Perhaps the most prolific form of Web advertising is the banner ad. It is a long, rectangular image that can be placed just about anywhere on a Web page. Most banner ads are 468 pixels wide by 60 pixels high (468x60). They may contain text, images, or sometimes those annoying animations that make it hard to focus on the page's content. Regardless of the type of banner ad, when a user clicks the advertisement, he or she is redirected to the advertiser's website.

Stands for "Beginner's All-purpose Symbolic Instruction Code." BASIC is a computer programming language that was developed in the mid-1960s to provide a way for students to write simple computer programs. Since then, the language has evolved into a more robust and powerful language and can be used to create advanced programs for today's computer systems.

BASIC originally used numbers at the beginning of each instruction (or line) to tell the computer what order to process the instructions. Lines would be numbered as 10, 20, 30, etc., which would allow additional instructions to be placed between commands later on if needed. "GOTO" statements enabled programs to loop back to earlier instructions during execution. For example, line 230 of a BASIC program may have an "if" clause that tells the computer to jump back to line 50 if a variable is less than 10. This instruction might look something like this:

230 IF (N < 10) THEN GOTO 50

More modern BASIC implementations use "while loops," which perform a series of instructions as long as a certain case is true. Newer BASIC development software also supports more data types, such as integers, strings, and arrays, for storing variables and other data. While the first BASIC development environments were strictly text-based, today's BASIC programming software allows developers to design much of their programs visually, using a graphical user interface. Some of the more popular BASIC development programs used today include REALbasic and Microsoft Visual Basic.

A batch file is a type of script that contains a list of commands. These commands are executed in sequence and can be used to automate processes. For example, some programs may include a batch file that executes a number of commands as the program starts up. A user can also create a custom batch file to automate tedious processes such as copying multiple directories or renaming several files at once.

Batch files are run by the COMMAND.COM program, which is part of DOS and Windows. Therefore, batch files can only be run within the Windows operating system. Macintosh and Unix have other scripting tools, such as AppleScript and Unix shell commands, that can be used for similar tasks. Because batch files contain executable commands, it is important not to open unknown batch files on your hard disk or in e-mail attachments.

Contrary to popular belief, baud is not a direct measurement of data transfer speed, but instead it measures how many electrical signals are sent per second. Baud is used to measure the rate of electrical signals, or "signaling elements," for modems, networks, serial cables, and other data transfer mediums.

Some people think that baud and bits per second are equal. For example, they'll say a 28,800 bps modem transmits at 28,800 baud, and act like they know everything. But the fact is, most modems transmit multiple bits of data per baud, so while the the two values are related, they are typically not equal. So the next time your friend says his 56K v.90 modem can transfer data at 56,000 baud, you can kindly tell him that he is incorrect and explain to him the difference between baud and bps.

Stands for "Blind Carbon Copy." When you send an e-mail to only one person, you type the recipient's address in the "To:" field. When you send a message to more than one person, you have the option to enter addresses in the "Cc:" and "Bcc:" fields. "Cc" stands for "Carbon Copy," while "Bcc" stands for "Blind Carbon Copy."

A carbon copy, or "Cc'd" message is an e-mail that is copied to one or more recipients. Both the main recipient (whose address is in the "To:" field) and the Cc'd recipients can see all the addresses the message was sent to. When a message is blind carbon copied, neither the main recipient nor the Bcc'd recipients can see the addresses in the "Bcc:" field.

Blind carbon copying is a useful way to let others see an e-mail you sent without the main recipient knowing. It is faster than sending the original message and then forwarding the sent message to the other recipients. It is also good netiquette to use Bcc when copying a message to many people. This prevents the e-mail addresses from being captured by someone in the list who might use them for spamming purposes. However, if it is important that each recipient knows who your message was sent to, use carbon copy (Cc) instead.

Binary is a two-digit (Base-2) numerical system, which computers use to store data and compute functions. The reason computers use the binary system is because digital switches inside the computer can only be set to either on or off, which are represented by a 1 or 0. Though the binary system consists of only ones and zeros, the two digits can be used to represent any number.

For example:

A single 0 in binary represents zero.
A single 1 represents (2^0) or 1.
10 represents (2^1) or 2.
11 represents (2^1 + 2^0) or 3.
100 represents (2^2) or 4.
101 represents (2^2 + 2^0) or 5.
110 represents (2^2 + 2^1) or 6.
111 represents (2^2 + 2^1 + 2^0) or 7.
1000 represents (2^3) or 8, and so on.

Stands for "Basic Input/Output System." Most people don't need to ever mess with the BIOS on a computer, but it can be helpful to know what it is. The BIOS is a program pre-installed on Windows-based computers (not on Macs) that the computer uses to start up. The CPU accesses the BIOS even before the operating system is loaded. The BIOS then checks all your hardware connections and locates all your devices. If everything is OK, the BIOS loads the operating system into the computer's memory and finishes the boot-up process.

Since the BIOS manages the hard drives, it can't reside on one, and since it is available before the computer boots up, it can't live in the RAM. So where can this amazing, yet elusive BIOS be found? It is actually located in the ROM (Read-Only Memory) of the computer. More specifically, it resides in an eraseable programmable read-only memory (EPROM) chip. So, as soon as you turn your computer on, the CPU accesses the EPROM and gives control to the BIOS.

The BIOS also is used after the computer has booted up. It acts as an intermediary between the CPU and the I/O (input/output) devices. Because of the BIOS, your programs and your operating system don't have to know exact details (like hardware addresses) about the I/O devices attached to your PC. When device details change, only the BIOS needs to be updated. You can make these changes by entering the BIOS when your system starts up. To access the BIOS, hold down the key as soon as your computer begins to start up.

The computer term "bit" comes from the phrase "Binary DigIT," which is different than that thing you put around a horse's mouth. A bit is a single digit number in base-2 (a zero or a one) and is the smallest unit of computer data. A full page of text is composed of about 16,000 bits.

It is important not to confuse bits with bytes. Both are used to measure amounts of data, but it takes eight bits to make one byte. The most common area where bits are used intstead of bytes is in measuring bandwidth (in bits per second). Why? Probably because it makes your Internet connection sound faster than it really is.

Abbreviation: b