ActiveX -

ActiveX is the name Microsoft has given to a set of "strategic" object-oriented programming technologies and tools. The main technology is the Component Object Model (COM). Used in a network with a directory and additional support, COM becomes the Distributed Component Object Model (DCOM). The main thing that you create when writing a program to run in the ActiveX environment is a component, a self-sufficient program that can be run anywhere in your ActiveX network (currently a network consisting of Windows and Macintosh systems). This component is known as an ActiveX control. ActiveX is Microsoft's answer to the Java technology from Sun Microsystems. An ActiveX control is roughly equivalent to a Java applet.

If you have a Windows operating system on your personal computer, you may notice a number of Windows files with the "OCX" file name suffix. OCX stands for "Object Linking and Embedding control." Object Linking and Embedding (OLE) was Microsoft's program technology for supporting compound documents such as the Windows desktop. The Component Object Model now takes in OLE as part of a larger concept. Microsoft now uses the term "ActiveX control" instead of "OCX" for the component object. Currently, ActiveX controls run in Windows 95/98/NT/2000 and XP.

autoexec.bat -

backup -

Backup is the activity of copying files or databases so that they will be preserved in case of equipment failure or other catastrophe. Backup is usually a routine part of the operation of large businesses with mainframes as well as the administrators of smaller business computers. For personal computer users, backup is also necessary but often neglected. The retrieval of files you backed up is called restoring them.

• Backing up critical files to diskettes. This approach is commonly used by people who keep their checkbooks and personal finance data on the computer. Programs like Quicken and Managing Your Money always remind users when they quit the program to backup their data. If your hard disk crashes, you'll be able to reconstruct your checkbook balances. If you have other files (for example, chapters of a book you're working on), you'll want to backup every single day's work. Copying it to a diskette is quick and economical.
• Backing up to a Zip drive, Jaz, Syquest, or similar hard disks. Once a week or so, you should back up your files (at least your own data files and perhaps the entire contents of your hard drive) to an alternative storage device, such as a Zip drive. These devices hold at least one million bytes on a special hard disk. Backing up usually takes a while (about 45 minutes for the contents of a 500 megabyte hard disk).
• There are also easily removable drives that you can back up to, especially if you have other reasons to use these (for example, for large graphic images that you store offline).

bandwidth -

1) In electronic communication, bandwidth is the width of the range (or band) of frequencies that an electronic signal uses on a given transmission medium. In this usage, bandwidth is expressed in terms of the difference between the highest-frequency signal component and the lowest-frequency signal component. Since the frequency of a signal is measured in hertz (the number of cycles of change per second), a given bandwidth is the difference in hertz between the highest frequency the signal uses and the lowest frequency it uses. A typical voice signal has a bandwidth of approximately three kilohertz (3 kHz); an analog television (TV) broadcast video signal has a bandwidth of six megahertz (6 <TERM>MHz</TERM>) -- some 2,000 times as wide as the voice signal.

2) In computer networks, bandwidth is often used as a synonym for data transfer rate - the amount of data that can be carried from one point to another in a given time period (usually a second). This kind of bandwidth is usually expressed in bits (of data) per second (bps). Occasionally, it's expressed as <TERM>bytes per second</TERM> (Bps). A modem that works at 57,600 bps has twice the bandwidth of a modem that works at 28,800 bps. In general, a link with a high bandwidth is one that may be able to carry enough information to sustain the succession of images in a video presentation. It should be remembered that a real communications path usually consists of a succession of links, each with its own bandwidth. If one of these is much slower than the rest, it is said to be a bandwidth bottleneck.

BIOS -

BIOS (basic input/output system) is the program a personal computer's microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer's operating system and attached devices such as the hard disk, video adapter, keyboard, mouse, and printer.

BIOS is an integral part of your computer and comes with it when you bring it home. (In contrast, the operating system can either be preinstalled by the manufacturer or vendor or installed by the user.) BIOS is a program that is made accessible to the microprocessor on an eraseable programmable read-only memory (EPROM) chip. When you turn on your computer, the microprocessor passes control to the BIOS program, which is always located at the same place on EPROM.

When BIOS boots up (starts up) your computer, it first determines whether all of the attachments are in place and operational and then it loads the operating system (or key parts of it) into your computer's random access memory (RAM) from your hard disk or diskette drive.

With BIOS, your operating system and its applications are freed from having to understand exact details (such as hardware addresses) about the attached input/output devices. When device details change, only the BIOS program needs to be changed. Sometimes this change can be made during your system setup. In any case, neither your operating system or any applications you use need to be changed.

Although BIOS is theoretically always the intermediary between the microprocessor and I/O device control information and data flow, in some cases, BIOS can arrange for data to flow directly to memory from devices (such as video cards) that require faster data flow to be effective.

batch file -

A batch file is a text file that contains a sequence of commands for a computer operating system. It's called a batch file because it batches (bundles or packages) into a single file a set of commands that would otherwise have to be presented to the system interactively from a keyboard one at a time. A batch file is usually created for command sequences for which a user has a repeated need. Commonly needed batch files are often delivered as part of an operating system. You initiate the sequence of commands in the batch file by simply entering the name of the batch file on a command line.

In the Disk Operating System (DOS), a batch file has the file name extension ".BAT". (The best known DOS batch file is the AUTOEXEC.BAT file that initializes DOS when you start the system.) In Unix-based operating systems, a batch file is called a shell script. In IBM's mainframe VM operating systems, it's called an EXEC.

baysian filter -

A Bayesian filter is a program that uses Bayesian logic, also called Bayesian analysis, to evaluate the header and content of an incoming e-mail message and determine the probability that it constitutes spam. Bayesian logic is an extension of the work of the 18th-century English mathematician Thomas Bayes.

Bayesian filters aren't perfect, but because spam characteristically contains certain types of text, such a program can be amazingly effective when it is fine-tuned over a period of time. A Bayesian filter works by categorizing e-mail into groups such as "trusted" and "suspect," based on a probability number (ranging from 0 or 0% to 1 or 100%). The categories are defined according to user preference.

Spammers are constantly trying to invent new ways to defeat spam filters. Certain words, commonly identified as characteristic of spam, can be altered by the insertion of symbols such as periods, or by the use of nonstandard but readable characters such as Â, Ç, Ë, or Í. But as the user instructs a Bayesian filter to quarantine or delete certain messages, the filter incorporates this data into its future actions. Thus a Bayesian filter improves with time, so it becomes more likely to block spam without also blocking desired messages.

Bayesian filters are best used in conjunction with <TERM>anti-virus program</TERM>s. Malicious viruses or worms can occasionally appear as attachments to e-mail messages, even from trusted sources.

beep code -

A beep code is the audio signal given out by a computer to announce the result of a short diagnostic testing sequence the computer performs when first powering up (called the Power-On-Self-Test or POST). The POST is a small program contained in the computer's Basic Input/Output Operating System (BIOS) that checks to make sure necessary hardware is present and required memory is accessible. If everything tests out correctly, the computer will typically emit a single beep and continue the starting-up process. If something is wrong, the computer will display an error message on the monitor screen and announce the errors audibly with a series of beeps that vary in pitch, number and duration (this is especially useful when the error exists with the monitor or graphic components). The beeping sequence is really a coded message (beep code) designed to tell the user what is wrong with the computer.

There is no official standard for beep codes; audio patterns vary according to the manufacturer of the computer's BIOS program. If an error message is beeped on startup, the user must first determine what kind of BIOS the computer is running (Phoenix or AMI are the most popular) and use that information to look up the particular beep code sequence that is being sent. BIOS information and beep code interpretations can be found in the manual that comes with the computer and on the manufacturer's Web site.

benchmark -

A benchmark is a point of reference by which something can be measured. In surveying, a "bench mark" (two words) is a post or other permanent mark established at a known elevation that is used as the basis for measuring the elevation of other topographical points.

In computer and Internet technology, the term may have any of these meanings:

1) A set of conditions against which a product or system is measured. PC magazine laboratories frequently test and compare several new computers or computer devices against the same set of application programs, user interactions, and contextual situations. The total context against which all products are measured and compared is referred to as the benchmark.

2) A program that is specially designed to provide measurements for a particular operating system or application.

3) A known product with which users are familiar or accustomed to that other newer products can be compared to.

4) A set of performance criteria which a product is expected to meet.

Laboratory benchmarks sometimes fail to reflect real-world product use. For this reason, Eric Raymond defines a benchmark as "an inaccurate measure of computer performance" and cites the "old hacker's saying" that "In the computer industry, there are three kinds of lies: lies, damn lies, and benchmarks."

Still, benchmarks can be useful and some companies offer benchmark programs for downloading or a benchmark testing service on their own site.

beta test -

In software development, a beta test is the second phase of software testing in which a samplingof the intended audience tries the product out. (Beta is the second letter of the Greek alphabet.) Originally, the term alpha test meant the first phase of testing in a software development process. The first phase includes unit testing, component testing, and system testing. Beta testing can be considered "pre-release testing." Beta test versions of software are now distributed to a wide audience on the Web partly to give the program a "real-world" test and partly to provide a preview of the next release.

CD -

A compact disc [sometimes spelled disk] (CD) is a small, portable, round medium made of molded polymer (close in size to the floppy disk) for electronically recording, storing, and playing back audio, video, text, and other information in digital form. Tape cartridges and CDs generally replaced the phonograph record for playing back music. At home, CDs have tended to replace the tape cartridge although the latter is still widely used in cars and portable playback devices.

Initially, CDs were read-only, but newer technology allows users to record as well. CDs will probably continue to be popular for music recording and playback. A newer technology, the digital versatile disc (DVD), stores much more in the same space and is used for playing back movies.

Some variations of the CD include: CD-ROM CD-RW

CGI -

The common gateway interface (CGI) is a standard way for a Web server to pass a Web user's request to an application program and to receive data back to forward to the user. When the user requests a Web page (for example, by clicking on a highlighted word or entering a Web site address), the server sends back the requested page. However, when a user fills out a form on a Web page and sends it in, it usually needs to be processed by an application program. The Web server typically passes the form information to a small application program that processes the data and may send back a confirmation message. This method or convention for passing data back and forth between the server and the application is called the common gateway interface (CGI). It is part of the Web's Hypertext Transfer Protocol (HTTP).

If you are creating a Web site and want a CGI application to get control, you specify the name of the application in the uniform resource locator (URL) that you code in an HTML file. This URL can be specified as part of the FORMS tags if you are creating a form. For example, you might code: http://www.mybiz.com/cgi-bin/formprog.pl>

and the server at "mybiz.com" would pass control to the CGI application called "formprog.pl" to record the entered data and return a confirmation message. (The ".pl" indicates a program written in Perl but other languages could have been used.)

The common gateway interface provides a consistent way for data to be passed from the user's request to the application program and back to the user. This means that the person who writes the application program can makes sure it gets used no matter which operating system the server uses (PC, Macintosh, UNIX, OS/390, or others). It's simply a basic way for information to be passed from the Web server about your request to the application program and back again.

Because the interface is consistent, a programmer can write a CGI application in a number of different languages. The most popular languages for CGI applications are: C, C++, Java, and Perl.

An alternative to a CGI application is Microsoft's Active Server Page (ASP), in which a script embedded in a Web page is executed at the server before the page is sent.

checksum -

A checksum is a count of the number of bits in a transmission unit that is included with the unit so that the receiver can check to see whether the same number of bits arrived. If the counts match, it's assumed that the complete transmission was received. Both TCP and UDP communication layers provide a checksum count and verification as one of their services.

chip set -

CHTML -

Compact HTML (CHTML or cHTML) is a subset of standard Hypertext Markup Language (HTML) adapted for use with small computing devices such as personal digital assistants (PDAs), cellular phones, and smartphones. Access Company Ltd., a Japanese company, developed Compact HTML for use with i-Mode devices. Because handheld devices have display constraints, and limited power, storage, and memory resources, Compact HTML was created as a stripped-down version of the standard, excluding support for the more demanding features of HTML pages, such as image maps, backgrounds, varieties of fonts, frames , style sheets, and JPEG images.

Compact HTML includes support for GIF images, and uses four buttons for operation, rather than two-dimensional cursor movement. Scrolling is not featured, because it is assumed that pages properly designed will fit the screen. Because Compact HTML is based on the universally used standard, it will enable small devices to connect to the open Web, rather than merely a section of it. It is expected that, in the future, several different levels of Compact HTML will be developed to adapt to the requirements of different applications.