What distinguishes a differential backup from an incremental backup?

A differential backup is characterized by its inclusion of all changes made to data since the last full backup. This means that each time a differential backup is performed, it captures every file that has been modified or added since that particular full backup. In contrast to incremental backups, which only save changes made since the previous backup (whether it was a full or incremental backup), differential backups compound all changes from the last full backup.

This approach allows for easier data restoration since you only need the last full backup and the most recent differential backup to recover the data. The complexity of managing multiple incremental backups is avoided, as differential backups streamline the restoration process by reducing the number of backups needed to be searched through. This makes option C the correct distinction in identifying a differential backup.