folder - technical definition

In a graphical user interface (GUI), a simulated file folder that holds data, applications and other folders. Folders were introduced on the Xerox Star, then popularized on the Macintosh and later adapted to Windows and Unix. In Unix and Linux, as well as DOS and Windows 3.1, a folder is called a "directory," and a subfolder (folder within a folder) is a "subdirectory." See Win Folder organization.