Which backup type copies only files that have changed since the last backup, with the last backup potentially being of any type?

Which backup type copies only files that have changed since the last backup, with the last backup potentially being of any type?

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

Answer: (A)

Incremental backups work by recording only the data that has changed since the last backup. The reference point can be the previous backup of any type, whether that last backup was full or incremental, so each new backup contains just the deltas since that prior snapshot. This makes incremental backups fast and storage-efficient because you’re not re-copying everything every time. For restoring, you typically need the initial full backup plus every incremental backup in the sequence to reconstruct the latest state, since each incremental only contains the changes since the previous one. This differs from a full backup, which copies all files regardless of changes; a differential backup, which collects changes since the last full backup; and a mirror backup, which is a direct, exact copy of the source at a point in time rather than a delta set.

Incremental backups work by recording only the data that has changed since the last backup. The reference point can be the previous backup of any type, whether that last backup was full or incremental, so each new backup contains just the deltas since that prior snapshot. This makes incremental backups fast and storage-efficient because you’re not re-copying everything every time.

For restoring, you typically need the initial full backup plus every incremental backup in the sequence to reconstruct the latest state, since each incremental only contains the changes since the previous one.

This differs from a full backup, which copies all files regardless of changes; a differential backup, which collects changes since the last full backup; and a mirror backup, which is a direct, exact copy of the source at a point in time rather than a delta set.