Differential Backup
A differential backup scheme, also called “cumulative incremental backups,” starts with the first full copy. The second one contains only the data changed since the last full backup performed—just like an incremental backup.
However, when it comes to the third and following copies, they will only consist of changes, though always in relation to the last full copy. This is the opposite of an incremental backup, where the following copy compares data with a previously done incremental backup.
Differential backup requires more storage and, in most cases, prolonged periods of time to complete than the incremental backup approach. The rule here is simple: the further from the last full copy, the larger the copies are. That said, differential backup enables faster recovery because only two backup sets are required to restore your assets (the last differential backup and the last full copy).
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