Definition: mass storage

Permanent peripheral storage, which is typically a hard drive or solid state drive (SSD). It may also refer to a magnetic tape library. Mass storage is an old term that refers to storage, which was always much larger (more "massive") than main memory (RAM). Still true today, trillions of bytes (terabytes) of storage are commonly available compared to a few billion bytes (gigabytes) of RAM. See storage vs. memory.

If the term is used today, it means a huge amount of storage such as in a storage area network (SAN) or storage array and not the capacities found in a single computer or server (see SAN and storage array). See flash memory, magnetic disk, optical disc and magnetic tape.

Mass Storage on a Deck of Cards

In the 1960s, a roomful of these Card Random Access Memory (CRAM) units provided 176 megabytes of direct access mass storage, a huge capacity for that era. See CRAM for more details. (Image courtesy of NCR Corporation.)