Recommended Backup
If you are new Ubuntu user or aren't sure what you should
backup.This will perform a daily backup of your /home,system data
held in /etc,/usr/local and /var.This will deliberately exclude any
files over 100MB.By default this backup will be stored
/var/backup
Custom Backup
This is same as the recommended backup and in this you can change
the settings include,exclude files,you can change the schedule
time.
Manual Backup
If you want to backup some files from time to time this option is
for you and you can click backup now button to manually perform a
backup according to the settings on the other backup properties
dialog box tabs.