Data Protection · Visual Explainer
Full vs Incremental vs Differential Backups
The concept
Full copies everything every time — slow to make, one file to restore. Incremental copies only what changed since the last backup of any kind — fastest to make, but restore needs the full plus the entire chain. Differential copies everything since the last full — grows daily, but restore only ever needs two files.
Key distinctions
| Term | What it means |
|---|---|
| Full | Simple, storage-hungry, fastest restore. The weekly anchor of most schemes. |
| Incremental | Each references the previous backup. Fastest and smallest, but restore needs the full plus every link — and one corrupt link breaks the chain. |
| Differential | Each references the last full. Grows through the week, but restore is always just two files. |
| The design question | It's RTO and RPO — how long can you be down, how much data can you lose. Those two numbers are the strategy. |
Why it matters in practice
A backup that has never been restore-tested is a hypothesis, not a backup. You choose based on restore day, not backup night.