Computer file

A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape.

Related Topics:
Computer - Bit - File system - Disk - Magnetic tape

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While a file is usually presented as a single stream, it most often is stored as multiple fragments of data at different places on a disk (or even multiple disks). One of the services operating systems usually perform for applications is that of organization of files in a file system.

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Files are created by software and usually conform to a particular file format. They are almost always assigned file names by the file system on which they are stored, so that they can be referred to at a later time.

Related Topics:
Software - File format

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Some operating systems allow the contents of a file to be segmented into fixed and variable length records. For example, OpenVMS allows any arbitrary set of characters to be defined as the terminators to variable length record within a file. Others, like Microsoft Windows, have only one specialised subclass of file, called a text file, where a sequence of characters separate the data into lines of text (a specialised variable length record). Some operating systems, such as UNIX, do not handle file records at the operating system level, instead it is done at the application level. See record-oriented filesystem.

Related Topics:
Operating systems - OpenVMS - Microsoft Windows - Text file - Characters - UNIX - Record-oriented filesystem

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A special file is a file system object which is accessed as though it was a file, but the sequence of bits is supplied or consumed by another process (or by the operating system itself) such as a device driver or network interface. Indeed, the philosophy that "everything is a file" is one of the best known design decisions in Unix and Unix-like operating systems (such as Linux).

Related Topics:
Process - Device driver - Network interface - Unix and Unix-like operating systems - Linux

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Files are often organized hierarchically by the operating system, placing them in directories.

Related Topics:
Hierarchically - Directories

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