Which backup type backs up all changes made since the last full backup?

Which backup type backs up all changes made since the last full backup?

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

Answer: (B)

Differential backups capture all changes since the last full backup. After you perform a full backup, each differential backup includes every file that has changed since that baseline. This means you can restore by applying the most recent differential to the full backup, giving a complete restore without needing every intervening backup. The size of differential backups grows over time until the next full backup resets the baseline. By contrast, incremental backups only record changes since the last backup of any type, requiring the full backup plus every incremental to restore. A mirror backup is an exact copy of the current data, not a delta relative to a full backup. So the backup type that backs up all changes since the last full backup is the differential backup.

Differential backups capture all changes since the last full backup. After you perform a full backup, each differential backup includes every file that has changed since that baseline. This means you can restore by applying the most recent differential to the full backup, giving a complete restore without needing every intervening backup. The size of differential backups grows over time until the next full backup resets the baseline. By contrast, incremental backups only record changes since the last backup of any type, requiring the full backup plus every incremental to restore. A mirror backup is an exact copy of the current data, not a delta relative to a full backup. So the backup type that backs up all changes since the last full backup is the differential backup.