There are thousands of file formats, many that can be identified by their 3-letter file extension. To find out more, or to look for a particular format use http://www.wotsit.org/.
The following file formats are supported natively by Zetafax: ASCII, DCX, EPS bitmaps, Epson FX and LQ series, GIF, JPEG, PCX, PDF, PICT, Targa, TIFF, Windows metafile bitmaps, WordPerfect metafile bitmaps.
The type of code in which a data file is written, and indicated by a two-, three-, or four-letter extension at the end of the filename such as .txt for Plain ASCII Text, .ps for PostScript File, or .html for Document in Hypertext Markup Language.
The information of a digital file is stored in various file extensions / formats. The formats are either based in the application program that created the file, .psd is a PhotoShop file for example, or a more universal format that is supported by most imaging programs. Tiff and Jpeg. Some compress information in the image more so it creates smaller files. Whilst this is good for storage space and e mailing, information will be lost in the image when you come to print it. (tiff, jpeg, Psd, GIF, and EPS.)