External storage

This article is about external storage devices. For external storage in the context of data structures, see Reference (computer science)#External and internal storage.

In computing, external storage comprises devices that temporarily store information for transporting from computer to computer. Such devices are not permanently fixed inside a computer.

Semiconductor memories are not sufficient to provide the whole storage capacity required in computers. The major limitation in using semiconductor memories is the cost per bit of the stored information. So to fulfill the large storage requirements of computers, magnetic disks and optical disks are generally used.