What defines a differential backup?

What defines a differential backup?

• A. A backup of all data since the last backup
• B. A backup that copies only metadata
• C. A backup that duplicates the entire dataset daily
• D. A backup of data changed since the last full backup

Answer: (D)

A differential backup captures all data that has changed since the last full backup. After you perform a full backup, each differential backup includes every file that has changed since that full backup, so the set of changed data grows with time until the next full backup is performed. This distinguishes it from backing up only metadata or from duplicating the entire dataset every day. It also differs from an incremental backup, which copies changes since the last backup of any type rather than since the last full backup.

A differential backup captures all data that has changed since the last full backup. After you perform a full backup, each differential backup includes every file that has changed since that full backup, so the set of changed data grows with time until the next full backup is performed. This distinguishes it from backing up only metadata or from duplicating the entire dataset every day. It also differs from an incremental backup, which copies changes since the last backup of any type rather than since the last full backup.