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

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

Answer: (A)

Backups that capture all data changed since the last full backup are called differential backups. This method uses the last full backup as a baseline and includes every file that has changed since then, making restoration straightforward: restore the last full backup, then apply the most recent differential backup to bring data up to date.

Incremental backups, in contrast, store only changes since the last backup of any kind (last incremental or last full), which creates a chain of backups needed to restore. A full backup copies everything, not just changes. Archive backups are for long-term storage and retention, not specifically for daily changes.