Learning Web Design: Glossary

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24-bit color: A color model capable of displaying approximately 16,777,216 colors.[TOP]
8-bit color: A color model capable of displaying a maximum of 256 colors, the maximum number that 8 bits of information can define.
absolute pathname: Directions to a file's location on the server, starting at the topmost level of the server. An absolute URL begins by defining the HTTP protocol, followed by the name of the server and the complete pathname.
aliasing: The jagged, "stair-stepped" edges that can appear between colors in a bitmapped graphic.
alternative text: Text that is provided within an image tag that will display in the browser window if the image is not visible. It is specified using the ALT attribute within the <IMG> tag.
anchor: Another word for a link.
anti-aliasing: A slight blur added to the edges of objects and type in bitmapped graphics to smooth out the edges.
applet: A self-contained, mini-executable program, such as one written in the Java programming language.
attribute: Parameters added within an HTML tag to extend or modify its actions.
bit-depth: In web design, a measurement of the number of colors based on the number of bits (1s and 0s) allotted by the file or the system. A bit is the smallest unit of information on a computer (one bit can define 2 colors). Strung together, they can represent more values (8 bits can represent 256 values).
bitmapped image: A graphic that is made up of a grid of colored pixels, like a tiny mosiac. See also vector graphic. [TOP]
block element: In HTML, a distinct unit of text that is automatically displayed with space above and below.
browser: A piece of software that displays web pages.
Cascading Style Sheets: An addition to HTML for controlling presentation of a document, including color, typography, alignment of text and images, etc.
CGI: Common Gateway Interface; a mechanism for communication between the web server and other programs (CGI scripts) running on the server.
character entity: A string of characters used to specify characters not found in the normal alphanumeric character set in HTML documents.
container tag: An HTML tag that has both an opening tag (e.g., <H1>) and a closing tag (e.g, </H1>).
CSS: See Cascading Style Sheets.
DHTML: Dynamic HTML; an integration of JavaScript, HTML, and Cascading Style Sheets. DHTML can be used to make content respond to user input or for adding simple animation effects.
dithering: The approximation of a color by mixing pixels of similar colors that are available in the image or system palette. The result of dithering is a random dot-pattern or noise in the image.
domain name: A name that corresponds to a specific IP address. It is easier for humans to remember than a 12-digit IP address.
Flash: A multimedia format developed by Macromedia for the delivery of animation, interactivity, and audio clips over the Web.
frames: A method for dividing the browser window into smaller subwindows, each displaying a different HTML document.
FTP: File Transfer Protocol; a system for moving files over the Internet from one computer to another. [TOP]
gamma: Refers to the overall brightness of a computer monitor's display.
GIF: Graphic Interchange Format; common file format of web graphic images. GIF is a palette-based, 8-bit format. It is most appropriate for images with areas of flat color and sharp contrast.
hexadecimal: A base-16 numbering system consisting of the characters 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F (where A through F represent the decimal values 10 through 15). It is used in HTML for specifying color values.
HTML: HyperText Markup Language; the format of web documents.
HTTP: Hypertext Transfer Protocol; the system that defines how web pages and media are requested and transferred between servers and browsers.
host: Another term for a server. Hosting services are companies that provide server space for web sites. See also ISP.
imagemap: A single image that contains multiple hypertext links.
IP address: A numeric identifier for a computer or device on a network. An IP address has four numbers (from 0 to 255) separated by periods (.).
ISP: Internet Service Provider; the company that sells access to the Internet computer network, whether through a dial-up modem connection, DSL, ISDN, cable, or other connection.
Java: A cross-platform, object-oriented programming language developed by Sun Microsystems. It is typically used for developing large, enterprise-scale applications, but it can also be used for creating small applications for the Web in the form of applets.
JavaScript: A scripting language developed by Netscape that adds interactivity and conditional behavior to web pages.
JPEG: A lossy graphics compression scheme developed by the Joint Photographic Experts Group. JPEG is most efficient at compressing images with gradations in tone and no sharp edge contrasts, such as photographs.
MP3: A popular file format for high-quality audio that uses MPEG compression.
MPEG: A family of multimedia standards created by the Motion Picture Experts Group, commonly used to refer to audio and video files saved using one of the MPEG compression schemes.
nesting: Placing one set of HTML tags within another tag pair, usually resulting in a combination of styles or a hierarchical display (as in lists).
optimizing: Reducing file size. Optimizing is an important step in web development, where file size and transfer time are critical.
palette: A table in an 8-bit indexed color file (such as a GIF) 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 (/). [TOP]
pixel: A single square in a graphic image (short for Picture Element).
PNG: Portable Network Graphic; a versatile graphics file format that features support for both 8-bit (PNG8) indexed images and 24-bit images (PNG24). PNGs also feature variable transparency levels, automatic color correction controls, and a lossless, yet highly efficient, compression scheme.
QuickTime: A system extension that makes it possible to view audio and video information on a computer. It was originally developed for the Macintosh, but is now available for Windows as well. The term also refers to the file format.
relative pathname: Directions to a file based on the location of the current file.
resolution: The number of pixels per inch (ppi) in an online graphic. In print, resolution is measured in dots per inch (dpi).
RGB color: A color system that describes colors based on combinations of red, green, and blue light.
rollover: The act of passing the mouse pointer over an element's space, or the events triggered by that action (such as a changing graphic or pop-up message).
server: A networked computer that provides some kind of service or information.
Shockwave: Proprietary technology from Macromedia for the web delivery of multimedia content
standalone tag: An HTML tag (e.g., %lt;IMG>) that places an object on the page and does not use a closing tag (%lt;/>).
Unix: A multiuser, multitasking operating system developed by Bell Laboratories. It also provides programs for editing text, sending email, preparing tables, performing calculations, and many other specialized functions that normally require separate applications.
URL: Universal Resource Locator; the address of a site or document on the Web.
vector image: A graphic that uses mathematical equations to define shapes and fills. Vector images can be resized without change in quality. See also bitmapped image.
W3C: The World Wide Web Consortium; a consortium of many companies and organizations that "exists to develop common standards for the evolution of the World Wide Web." It is run by a joint effort between the Laboratory for Computer Science at the Massachusetts Institute of Technology and CERN, the European Particle Physics Laboratory, where the WWW was first developed.
web palette: The set of 216 colors that will not dither or shift when viewed with browsers on 8-bit monitors.
XML: eXtensible Markup Language; a new standard for marking up documents and data. XML allows authors to create customized tag sets that make content perform as databases and provide functionality not available with HTML.