A collection of information stored under a unique name, often in the form “name.extension” where the extension identifies the type of file and, usually implies what kind of program can open or view it. On the Web, common types of files are: page files (.htm, .asp, .jsp, .cfm, and so on), image files (.gif, .jpg, .png, and so on), applet files (.js, among others), non-page document files (.doc, .txt, .pdf, and so on.), and style files (.css, among others). While a page file is technically different from a page (see Page), a page will always include a page file.