As you surf the web, exchange email with other users, participate in newsgroups, and use anonymous FTP, you will notice a variety of file formats. Zip files and archived files are compressed formats. Examples of various file types and extensions appear in the table below. A file's extension will usually indicate the format in which the file is saved. Special software is required to view a graphic or listen to a sound.
Many files use a combination of formats.
For example, a file might be a compressed archive of a collection of graphic images. Fortunately, standard file naming conventions reveal the format of files. Files that use a combination of formats have several extensions, each separated by a period. Z is a compressed archived collection of Bugs Bunny sounds. The Z extension indicates Unix compression, and the tar extension stands for tape archive, a common format used to archive collections of files.