Backup copies are duplicate copies of data or of the entire hard drive on a separate storage medium. They are very important as if something happens to your date, you always have a recent copy to rely on, decreasing the damage you will have.
According to PCMAG, backup storage is a storage device used to hold copies of data for backup and recovery. In large enterprises, magnetic tape libraries and magnetic disks are used for backup (see tape library and D2D). Optical technologies have also been used (see magneto-optic disk and worm).
Myriad backup services on the Internet are available for both enterprises and consumers (see cloud storage).