Differential Backup
A differential backup is a subset of a full backup. The data in a differential backup consists of only the data which has changed since the last full backup operation. If an organization relies on differential backup to protect its data, then to accomplish a data restore, you must restore the most recent full backup, and then also restore the latest differential backup. The concept of incremental and differential backups was developed to address the difficulties in making backup of large systems to tape. Tape systems are slow and costly, and both incremental and differential backup offer a means to short-cut the backup process on a daily basis.
