A Backup is defined as a copy of files made at a certain point of time. If computer files get corrupted, one can restore the backup and thus recreate the corrupted files as they were at the time the backup was done. A backup is considered as an intermediary component in a total backup solution.
File History is a Windows feature that makes intermittant backups of the files contained in your libraries, Desktop, Contacts, and Favorites. The near real-time backups are stored on an attached external drive.