• Directory of Internet terms
  • Extension — In computer jargon an extension is an optional addition, usually consisting of a dot plus three or four letters, to the name of a File. The extension to the filename helps the computer (and the user) recognise what type of file it is and what it may contain, e.g. .doc is a Word document file, .exe is a computer program, .jpg or .jpeg is a picture file, and .htm or .html is a Web page file. See the following websites for further information on file extensions, what they mean, and links to sites offering utilities for managing and converting different types of files: Dot What!? http://www.dotwhat.net File Extensions: http://www.file-extensions.org Fileinfo: http://www.fileinfo.com