|  | 14.1 | The Presentation Layer
| 14.1.2 | File formats

ASCII and EBCDIC are used to format text. ASCII text files contain simple character data, and lack any sophisticated formatting commands, such as boldface or underline. Notepad is an example of an application that uses and creates text files. They usually have the extension .txt. EBCDIC is very similar to ASCII in that it also does not use any sophisticated formatting. The main difference between the two is that EBCDIC is primarily used on mainframes and ASCII is used on personal computers.

Another common file format is the binary format. Binary files contain special coded data that can only be read by specific software applications. Programs such as FTP use the binary file type to transfer files. Networks use many different types of files. A previous section briefly touched on graphic file formats. The Internet uses two binary file formats to display images - Graphic Interchange Format (GIF), and Joint Photographic Experts Group (JPEG). Any computer with a reader for the GIF and JPEG file formats can read these file types, regardless of the type of computer. Readers are software programs designed to display an image of a particular file type. Some programs can read multiple image types as well as convert files from one type to another. Web browsers have the ability to display graphic files in either of these two formats without any additional software.

The multimedia file format is another type of binary file, which stores sounds, music, and video. Sound files generally operate in one of two ways. They may be completely downloaded, first, and then played, or they may download while they are playing. The latter method is referred to as streaming audio. Windows uses the WAV format for sound, and the AVI format for animation files. A few of the more common video formats are MPEG, MPEG2, and Macintosh QuickTime.

Another type of file format is markup language. This format acts as a set of directions that tell a Web browser how to display and manage documents. Hypertext Markup Language (HTML) is the language of the Internet. HTML directions tell a browser whether to display text, or to hyperlink to another URL. HTML is not a programming language, but is a set of directions for displaying a page.