What is synthetic backup?
A synthetic backup takes a full backup of a file and then changes that file with one or more incremental backups. The first incremental backup is only made from data that has changed since the full backup.
Subsequent incremental backups consist only of changed data from the last full backup. It is called a synthetic backup because it was not created from original data, but was created from two or more files that were merged or synthesized by the backup application.
Synthetic backups are used when time or the system does not allow a full backup. Applications that perform synthetic backups are not limited to individual computer files. They can be used to back up entire folders or the contents of entire hard drives.
The purpose of synthetic backup is to provide quick backups and reduce the cost and time of data recovery.