A computer file is a resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished. Computer files can be considered as the modern counterpart of paper documents which traditionally are kept in offices' and libraries' files, and this is the source of the term.
The word "file" was used publicly in the context of computer storage as early as February, 1950. In an RCA (Radio Corporation of America) advertisement in Popular Science Magazine describing a new "memory" vacuum tube it had developed, RCA stated:
Microsoft Windows is a series of graphical interface operating systems developed, marketed, and sold by Microsoft.
Microsoft introduced an operating environment named Windows on November 20, 1985 as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUI). Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984.