Backing up only the data that has changed since the last full or incremental backup is called what?

• A. Incremental backup
• B. Differential backup
• C. Full backup
• D. Archive backup

Answer: (A)

Incremental backups capture only data that has changed since the last backup, whether that last backup was a full backup or another incremental. After the initial full backup, each subsequent backup records only the new or modified files, which keeps backup time and storage small. However, restoring requires the full backup plus every incremental backup in the correct order.

Differential backups, by contrast, include all changes since the last full backup, so their size grows each day until the next full backup. A full backup copies everything, and an archive backup is for long-term retention rather than daily restore of recent changes.

So, backing up only what has changed since the last full or incremental backup is the essence of an incremental backup.