Other types of memory include the CD ROM and the DVD ROM (sometimes referred collectively as optical drives), and flash memory more commonly called the USB data
card amongst other types of specialist drives. The advantage of these memory devices is that they can be easily removed from a computer system.

Storage devices record data over their storage surface. The data may be stored in different ways according to the device. These include: optical optical data storage memory, magnetic media storage and mechanical storage media etc. Flash memory devices use yet another method. Storage devices are actually defined as the peripheral unit which holds data like the tape, disk, or flash memory card etc.