The concept of a file is central to the effective use of a computer system. A file is generally loosely defined as a collection of related information such as students records employee database.
It might contain graphical usage. A file may be organized internally into records or it may simply be a stream of bytes. A file constitutes a logical unit of storage, that is, logical to the person or program using the file.
The file management system provides and maintains the mapping between a file logical storage needs and the physical location where it is stored. Users and programs simply access the files by the name, and the file management system handles the details The file management system identifies and manipulates files by the names provided by their users determines the physical requirements of the file, allocate space for it, stores it in that space, and maintains the information about the file so that it may be retrieved partially or in full, later. The file management system keeps track of the available space on each device connected to the system. The user and the user's program need not be aware of the underlying physical storage issues.