| A | B |
| Absolute unit | Font size definitions that use one of five standard units of measurement. |
| Animated GIF | An image composed of several images that are displayed one after the other. |
| Client-side image map | An image map that is stored in an HTML file. |
| Color value | A numerical expression that precisely describes a color. |
| dithering | When a browser combines similar colors from its palette to approximate the original color’s appearance. |
| Dpi | Dots per inch, a unit of measurement of the resolution of an output device. |
| Em unit | A unit of measurement of font size, equal to the width of the capital letter “M.” |
| Ex unit | A unit of measurement of font size, equal to the height of the lowercase letter “x.” |
| Flash | A proprietary graphics format from Macromedia. |
| Generic font | A name for a general description of a font’s appearance. |
| GIF | Graphics Interchange Format; a commonly used graphics format on the Web. |
| Hanging indent | A paragraph format that extends the first line of text to the left of the text block. |
| Hexadecimal | A number expressed in base 16, used to express color values. |
| Hotspot | A specific area of a graphic that has its own link. |
| Image map | A tag that lists the boundaries of all hotspots in a graphic. |
| Interlacing | The method by which a software product saves and retrieves a GIF image. |
| Kerning | The amount of space between pairs of letters. |
| Leading | The amount of space between lines of text. |
| Palette | A selection of colors. |
| Pixel | A unit of measurement that represents a single dot on an output device. |
| PNG Portable Network Graphics | graphics file format. |
| Web-safe colors | A palette of colors that are guaranteed not to dither in any Web browser. |
| Watermark | A fixed background image. |
| Transparent color | A color in a graphics file that is not displayed when the image is viewed in an application. |
| Tiling | The process of repeating an image horizontally and vertically until it fills up a page. |
| Server-side image map | An image map that is stored on a Web server. |