When a user selects Full backup, GMB will back up all the selected files and folders each time the backup job is run. New files will also be appended to the selection. On consecutive runs, in general, this backup type is more time and space consuming than the other three backup types, but is more user friendly.
To set GMB to always run a full backup, select Full, from the Settings screen in the backup wizard.
This backup type is best for one-time backups to migrate data between computers.