Non-volatile Auxiliary Storage: Disk, Tape and Flash

Non-volatile storage is storage that retains its contents while the power is off. This includes magnetic disks (hard disks), optical discs such as CD, DVD, and Blu-Ray, Flash devices such as USB thumb drives and SSDs, and magnetic tape.

Non-volatile storage is mainly used to store files containing programs or data, for use at a later time. It can also be used for virtually any other storage needs, however, as we will see shortly.