Definition of File format:
Specific structure or arrangement of data code stored as a computer file. A file format tells the computer how to display, print, and process, and save the data. It is dictated by the application program which created the file, and the operating system under which it was created and stored. Of the hundreds of file formats, most are incompatible with one another and may not be usable by other applications running under the same OS, or the same application running under a different OS. File formats that can be used under most or all OS include ASCII, Java by Sun Microsystems, Portable Document File (PDF) by Adobe Systems, Rich Text Format (RTF) by Microsoft Corp., Tagged Image File (TIF), as well as the file formats of documents created with Hypertext Markup Language (HTML), or Extensible Markup Language (XML).
Meaning of File format & File format Definition