A tape library is a storage device that contains one or more tape drives, a number of slots to hold tape cartridges, a barcode reader to identify tape cartridges, and an automated method for loading tapes. It is also sometimes referred to as a tape silo, tape robot, or tape jukebox. A tape library is not just the place where tapes that are not currently being held in a silo are kept, but it is also the name of the location. Tape libraries have the capacity to store millions upon millions of tapes.
The IBM 3850 Mass Storage System (MSS), which was introduced in 1974, is considered to be one of the early instances.