Computer file
A computer file is a named collection of data treated as a unit by the system that manages it. Today, this system is called a file system. Many older computer systems lacked a distinct file system per se, yet a management feature is required in order to provide a file abstraction.
Files can be shared with and transferred between computers and mobile devices via removable media, networks, or the Internet.
Different types of computer files are designed for different purposes. A file may be designed to store a written message, a document, a spreadsheet, an image, a video, a program, or any wide variety of other kinds of data. Certain files can store multiple data types at once.
By using computer programs, a person can open, read, change, save, and close a computer file. Computer files may be reopened, modified, and copied an arbitrary number of times.