A backup is a copy of data—files, folders, databases, system images, or entire servers—stored separately so it can be restored if the original data is lost, damaged, or corrupted. Backups can be stored on external drives, network storage, cloud services, or backup appliances.
A full backup is the complete copy of all selected data at a specific point in time. It backs up everything—every file, folder, database, system configuration, or volume you choose—regardless of whether the data has changed since the last backup.
Differential Backup
A differential backup saves all data that has changed since the last full backup—not since the last differential. It sits in the middle between a full backup and an incremental backup in terms of speed, size, and restore complexity.
Incremental Backup
An incremental backup saves only the data that has changed since the last backup of any type—whether that last backup was full, differential, or another incremental. This makes incremental backups very fast and storage-efficient, but they create a longer “chain” to restore from.
