# Glossary

A | B | C | D | E | F | G | H | I | J | L | M | N | O | P | Q | R | S | T | U | V | W | X

## A

aliasing
  The jagged stair-stepped edges that can appear between colors in a bitmapped graphic.
anchor
  The HTML element responsible for making hyperlinks.
applet
  A self-contained, mini-executable program, such as one written in the Java programming language.
attribute
  Parameters that extend or modify an HTML element

## B

backend
  Aspects of a web site that pertain to functions that take place on the server
bit depth
  A measurement of colors based on the number of bits alloted by the file or system
browser
  The client software that requests and displays web pages.

## C

cache
  Temporary storage area that browsers use for downloaded documents
CGI
  Common Gateway Interface, a mechanism for communication between the web server and other programs running on the server
codec
  An algorithm used by media files for compressing and decompressing data
compression
  A method for reducing the file size of a document. Different file formats use different compression techniques

## D

dithering
  The approximation of a color by mixing pixels of similar colors that are available in the image or system palette.
Document Type Definition (DTD)
  An XML document that defines every element and attribute for a markup language.
domain name
  A name that corresponds to a specific IP address.

## E

extranet
  A web site or system that is available within a closed system and to select users outside that system, usually via a password.

## F

Flash
  A multimedia format for the delivery of animation, interactivity, and audio on the Web
frame rate
  In video and animation, the number of frames per second
FTP
  File Transfer Protocol; a system for moving files over the Internet from one computer to another

## G

gamma
  Refers to the overall brightness of a computer's monitor display.
GIF
  Graphic Interchange Format; common file format of web graphic images. GIF is a palette-based, 8-bit format.

## H

hexadecimal
  A base-16 numbering system that uses the characters 0-9 and A-F. It is used in CSS and HTML for specifying color values
host
  Another term for the server. Hosting services are companies that provide server space for web sites.
HTML
  HyperText Markup Language; the tagging language used to identify the structure of web documents.
HTTP
  Hypertext Transfer Protocol; the system that defines how web pages and media are requested and transferred between servers and browsers.

## I

imagemap
  A single image that contains multiple hypertext links
IP address
  A numeric identifier for a computer or device on a network.
ISP
  Internet Service Provider; a company that sells access to the Internet computer network

## J

Java
  A cross-platform, object-oriented programming language developed by Sun Microsystems.
JavaScript
  A scripting language that adds behaviors to elements on web pages and browsers.

## L

lossy
  A type of compression in which data is thrown out to reduce file size. The JPEG format uses a lossy compression scheme.

## M

MP3
  A popuplar file format for high-quality audio that uses MPEG compression
MPEG
  A family of multimedia standards created by the Motion Picture Experts Group

## N

nesting
  Placing one HTML element within another. HTML and XHTML define rules for what elements may be nested within another.

## O

optimizing
  Reducing file size to improve transfer time over the network.

## P

palette
  A table in an 8-bit indexed color file that provides color information for the pixels in the image.
pathname
  Directions to a file using a nomenclature in which directory hierarchies and filenames are separated by slashes
pixel
  A single square in a bitmapped graphic image
PNG
  Portable Network Graphic; a graphic file format that features support for 8-bit and 24 bit images

## Q

QuickTime
  An audio and video format developed by Apple Computer and available for all platforms

## R

resolution
  The number of pixels per inch (ppi) in a bitmapped image or computer monitor
RGB color
  A color system that describes color based on combinations of red, green, and blue light
root directory
  The top-level directory for a web site. The root directory contains all the files and subdirectories for a site.

## S

sans-serif font
  A font design featuring straight or squared off character strokes. Helvetica is an example.
serif font
  A font that has horizontal slabs at the ends of character strokes. Times is an example

## T

tweening
  A function in animation tools for automatically creating frames between a start and end frame.

## U

Unix
  A multi-user, multi-tasking operating system developed by Bell Laboratories.
URL
  Universal Resource Locator; the address of a document or resource on the World Wide Web

## V

vector image
  A graphic that uses mathematical equations to define shapes and fills. Vector images can be resized without change in quality.

## W

W3C
  The World Wide Web Consortium; a consortium of companies and organizations that develops common standards for the development of the Web.
web palette
  A set of 216 colors that is available on both Mac and Windows machines running 8-bit color monitors.

## X

XHTML
  The new HTML standard that has been written according to the rules of XML.
XML
  eXtensible Markup Language; a metalanguage for creating custom markup languages