Definitions of format:

• noun:   the general appearance of a publication
• noun:   the organization of information according to preset specifications (usually for computer processing)
• verb:   divide (a disk) into marked sectors so that it may store data

  Example: "Please format this disk before entering data!"

• verb:   determine the arrangement of (data) for storage and display (in computer science)
• verb:   set (printed matter) into a specific format

  Example: "Format this letter so it can be printed out"