While the term "snapshot" is often used in photography, it is also a computing term that refers to a copy made of a disk drive at a specific moment in time. Snapshots are useful for backing up data at different intervals, which allows information to be recovered from different periods of time.
A hard drive snapshot includes the full directory structure of a hard disk, including all folders and files on the disk. This type of backup may also be referred to as a "disk image." Disk images allow the full disk to be restored in case the primary disk fails. Many backup programs that create snapshots also allow specific files to be recovered from the snapshot, instead of having to restore the complete backup. Since snapshots are mainly used for backup purposes, it is wise to save the snapshot to a secondary hard drive, removable drive, or optical media, such as CDs or DVDs.