What type of backup retains all data regardless of previous backups?

A full backup is designed to create a complete copy of all selected data at a specific point in time. This means that it captures everything—files, folders, and system information—ensuring that nothing is left out. The major benefit of a full backup is that it simplifies data recovery because all necessary data can be restored from a single backup set.

In contrast to incremental and differential backups, which use previous backups to determine what to back up (with incremental only backing up changed files since the last backup and differential backing up all changes since the last full backup), a full backup retains the entire dataset regardless of any prior backups. Thus, while it may take more storage space and require longer to execute than other types, it provides a straightforward method for restoring data comprehensively.

Mirror backups also maintain a current copy of the data but could potentially remove data that has been deleted from the original source, which isn't the case with a full backup. Therefore, the distinguishing characteristic of a full backup is its ability to hold all backed-up data independently of previous backup states.