A collection of bytes stored as an individual entity. All data on disk is stored as a file with an assigned file name that is unique within the folder (directory) it resides in.

To the computer, a file is nothing more than a string of bytes. The structure of a file is known to the software that manipulates it. For example, database files are made up of a series of records. Word processing files contain a continuous flow of text.

Except for ASCII text files, which contain only raw text, other files have proprietary structures. Formatting and other types of information are contained in headers or interspersed throughout the file. Following are the major file types. See file association.

   Type                 Contents
   data file (table)    data records
   document             text
   spreadsheet          rows and columns of cells
   image                rows and columns of bits
   drawing              list of vectors
   audio                digitized sound waves
   MIDI                 MIDI instructions
   video                digital video frames
   Web page             text
   batch file           text
   source program       text
   executable program   machine language