What is the difference between differential backups and incremental backups?

• A. Differential backups copy all data changed since last full backup; incremental backups copy data changed since last backup
• B. Differential backups copy only the latest change; incremental copies all data changed since last full backup
• C. They are the same
• D. Differential backups copy data daily; incremental backups weekly

Answer: (A)

The main idea is how much data each type captures after your baseline backup. A differential backup records every file that has changed since the last full backup. That means each differential reflects all changes accumulated since that baseline, so the amount of data grows over time but restoration only needs the full backup plus the most recent differential.

An incremental backup, on the other hand, saves only what has changed since the previous backup (which could be the last incremental or the last full backup). This keeps each backup small, but restoring requires applying the full backup plus every incremental backup in order up to the point you want to restore.

So the correct distinction is that differential backups copy all changes since the last full backup, while incremental backups copy changes since the last backup of any type.