(1) A collection of files and certain attributes associated with those files.
(2) In the hierarchical file system, the underlying system support that manages I/O operations to files and controls the format of information on the storage media. A file system allows applications to create and manage files on storage devices and to perform I/O operations to those files.
(3) The collection of files and file management structures on a physical or logical mass storage device, such as a diskette or minidisk.