Which statement best distinguishes incremental backups from differential backups?

Which statement best distinguishes incremental backups from differential backups?

• A. Incremental backups copy only changes since the last backup; differential backups copy changes since the last full backup
• B. Incremental backups copy all files; differential backups copy only new files
• C. Incremental backups are slower to restore than differential backups
• D. Incremental backups require more storage than differential in all cases

Answer: (A)

The main idea is understanding exactly what each backup type records. Incremental backups store only the data that has changed since the last backup event (whether that last backup was full or incremental). This keeps each incremental backup small and fast to run, but to restore you must apply the base full backup plus every incremental backup in sequence to reach the latest state. Differential backups, in contrast, capture all changes since the last full backup. They grow larger over time because they don’t reset after each backup, but restoring is simpler—you only need the full backup plus the latest differential. So the best statement is that incremental backups copy only changes since the last backup, while differential backups copy changes since the last full backup. The other options misstate what is stored, or how restoration or storage needs work.

The main idea is understanding exactly what each backup type records. Incremental backups store only the data that has changed since the last backup event (whether that last backup was full or incremental). This keeps each incremental backup small and fast to run, but to restore you must apply the base full backup plus every incremental backup in sequence to reach the latest state. Differential backups, in contrast, capture all changes since the last full backup. They grow larger over time because they don’t reset after each backup, but restoring is simpler—you only need the full backup plus the latest differential.

So the best statement is that incremental backups copy only changes since the last backup, while differential backups copy changes since the last full backup. The other options misstate what is stored, or how restoration or storage needs work.