Glossary of terms

  • ASCII American Standard Code for Information Interchange, A seven-bit binary code standardized by ANSI (American National Standards Institute) for use by personal computers and some main-frames to represent alphanumeric and graphical characters. An additional bit is included to form an eight-bit character byte.
  • ARPA Advanced Research Projects Agency, the group withihn the US Department of Defense that developed ARPANET, the first major packet-switched network
  • buffer a temporary storage location that provides uninterrupted data flow between devices such as keyboards and processors or processors and printers until the data from one can be accepted by the other (also applies to temp storage memory allocated for use internally by software).
  • byte-code The contents of a Java .class file. This is readily converted at run-time to hardware specific routines. It is basically illegible to look at, so it's easier to protect a programmer's intellectual property when a program is in this form.
  • C-shell The C shell is a program that executes under the UNIX operating system. It is a command interpreter--the gateway to other programs and utilities running under UNIX (or Linux).
  • CGI Common Gateway Interface, protocol for server-side execution that feeds its output back through the http daemon and on to the client
  • client-server model A computer networking model wherein a server machine distributes its resources (as with telnet) and it's contents (as with httpd) to remote users. A balance must be maintained to insure that the server doesn't become overloaded with tasks.
  • delta compression Animation compression principle that isolates the parts of a frame that have changed since the last frame of animation.
  • Form tag A tag with several input properties that can pass data from a browser to a script, usually through the http - daemon using the CGI protocol
  • FTP file transfer protocol, TCP/IP application protocol governing file tranfer
  • GIF Graphics Interchange Format, image file format,supports 1-8 bit depth, special versions allow animation and transparency color, uses LZW compression
  • HTTP hyper text transfer protocol, protocol governing transmissions to and from web sites
  • incrementation The process whereby a variable is altered incrementally, generally within a loop
  • interpreted language Languages such as csh and BASIC are interpreted at run-time, ie, the commands of the script are evaluated directly from the file you edit and converted into machine-comprehensible code when the program is executed.
  • Java A simple, object-oriented, network-savvy, interpreted, robust, secure, architecture neutral, portable, high-performance, multithreaded, dynamic language. Also somewhat frustrating because it runs slowly on PC's which cannot convert its byte-code to native routines quickly enough to achieve performance levels equal to other languages like C and C++.
  • JPEG Joint Photographic Experts Group, file format that uses lossy compression techniques; good for photos
  • Linux A UNIX-like operating system that runs on PC's. Mostly it is used on Intel-based machines at this time. It is a collective effort, but its original groundwork was done by Linus Torvalds
  • LZW Lempel-Zev-Welch, a graphics compression technique that creates a dictionary of "phrases" found in an image to reduce the data needed to describe an image. Best on repetitive images and those with fewer colors.
  • MPEG Motion Picture Experts Group, format for video files, compressed in ways similar to JPEG, but also has delta compression
  • network A system of software and hardware connected in a manner to support data transmission
  • packet A collection of bits comprising data and control information formatted for transmission from one node to another.
  • packet switching A data transmission method that routes packets along the most efficient path and allows a communications channel to be shared by multiple connections
  • parsing The process of deciphering input data and formatting it so that it can be used in a program.
  • sandbox model The principle underlying Java's security is like a sandbox, because there are system resources within the "sandbox" available to a programmer, and other things are carefully protected. ActiveX does not adhere to this model.
  • SMTP Simple Mail Transfer Protocol, TCP/IP protocol governing electronic mail transmissions
  • TCP Transmission Control Protocol, TCP/IP protocol governing sequenced data
  • TCP/IP Transmission Control Protocol/ Internet Protocol, A protocol suite developed by ARPA (Advanced Research Projects Agency)
  • telnet TCP/IP protocol governing character-oriented terminal data Jargon Buster