Which type of backup only saves the changes made since the last full backup?

The type of backup that saves only the changes made since the last full backup is known as an incremental backup. This method is efficient because it focuses solely on the data that has changed, which reduces the amount of storage space needed and the time required to perform the backup.

Incremental backups work by first creating a full backup of the data, and then every subsequent backup captures only the files that have changed since the last incremental backup. This allows for quick restoration processes if needed, as the most recent full backup can be restored along with each incremental backup, effectively reconstructing the data.

Differential backups, on the other hand, save changes made since the last full backup, not the last differential backup. This means that each differential backup continues to grow over time since it captures all changes up to the most recent full backup. In contrast, an incremental backup resets after each incremental backup is completed.

Understanding these nuances is key in managing data backup strategies effectively, as each method serves different needs and goals regarding data protection and restoration speed.