back up is very to us because it brings back files and data which we are permanently deleted from our system . 
3 1 3
Backup provides you with the flexibility of managing the disk space that is used by your backups. After you set up Windows Backup, you can view how much disk space is being used by the backup and how much free space you have on the disk that your backups are being saved on by going to the Backup and Restore Control Panel..
3 4 3