Difference bettewn a Backup and a System Restor Point

What is the Difference bettewn a Backup and a System Restor Point and how can you use them?

backup is a complete mirror image (of everything or selected folders), system restore point only contains the "diffrence" and vital pointers of your OS state, not a whole mirror image (although I havent seen it fluke much)

System restorepoints and backups are mostly used with booting the windows cd to recovery, there you can do all that stuff.