This extension can be used for more than one thing. First is the process interchange format, a temporary file used to facilitate communication between different programs. There is also a rarely seen picture interchange format which can be used to store images. These two formats are both binary but can be used on pretty much any platform that has the appropriate support. The third possibility is a Microsoft program information file; it can be used only on MS-Windows machines and is in reality just what is more commonly called an alias, link, or shortcut.