Data, or information, can be held on fixed disk drives either inside the computer or on removable media such as CDs that can be inserted and removed. Removable storage media can be used to transfer files between computers or to backup the data already existing on fixed disk drives. There are three types of removable media: Magnetic, Optical and Flash.

Magnetic Storage:
Fixed and External Hard disks, floppy disks and digital audiotape are examples of Magnetic storage. They operate through a read/write head, which creates and reads magnetic impressions on the disk. Among the above Hard Disks and Floppy disks the recording surface is circular similar to gramophone records of earlier ages. Digital audio tapes are similar to audio recording tapes. However, for use with computers these magnetic tapes are highly improvised. Floppy disks are already extinct.