A computer file is a computer resource for recording data discretely in a computer storage device. Just as words can be written to paper, so can information be written to a computer file.
There are different types of computer files, designed for different purposes. A file may be designed to store a picture, a written message, a video, a computer program, or a wide variety of other kinds of data. Some types of files can store different several types of information at once.
By using computer programs, a person can open, read, change, and close a computer file. Computer files may be reopened, modified, and copied an arbitrary number of times.
Typically, computer files are organised in a file system, which keeps track of where the files are, and enables people to access them.
The word "file" derives from the Latin filum ("a thread").
"File" was used publicly in the context of computer storage as early as February 1950: In a Radio Corporation of America (RCA) advertisement in Popular Science Magazine describing a new "memory" vacuum tube it had developed, RCA stated: "the results of countless computations can be kept 'on file' and taken out again. Such a 'file' now exists in a 'memory' tube developed at RCA Laboratories. Electronically it retains figures fed into calculating machines, holds them in storage while it memorizes new ones - speeds intelligent solutions through mazes of mathematics."
In 1952, "file" denoted, inter alia, information stored on punched cards.
In early use, the underlying hardware, rather than the contents stored on it, was denominated a "file". For example, the IBM 350 disk drives were denominated "disk files". The introduction, circa 1961, by the Burroughs MCP and the MIT Compatible Time-Sharing System of the concept of a "file system" that managed several virtual "files" on one storage device is the origin of the contemporary denotation of the word. Although the contemporary "register file" demonstrates the early concept of files, its use has greatly decreased.