What does 'differential backup' involve?

Differential backup is a specific type of data backup that focuses on capturing only the data that has changed since the last full backup. This method is particularly efficient because it reduces the amount of data being backed up at any given time compared to a full backup, which includes everything in its entirety.

When a differential backup is performed, the data that has changed or been added since the last full backup is stored, making the restoration process faster than if multiple incremental backups were used. During recovery, you would first restore the last full backup and then apply the most recent differential backup.

This approach allows for a balance between backup time and storage requirements. It is also less time-consuming than taking full backups frequently while still ensuring that any changes are captured and can be restored if necessary. The emphasis on changes since the last full backup is what distinguishes differential backups from other backup types.