A revision guide by Tom Hill
Optical Storage: Optical storage is any storage method in which data is written and read with a laser for archival or backup purposes. Typically, data is written to optical media, such as CDs and DVDs. For several years, proponents have spoken of optical storage as a near-future replacement for both hard drives in personal computers and tape backup in mass storage. Magnetic Storage: The most common and enduring form of removable-storage technology is magnetic storage. For example, 1.44-MB floppy-disk drives using 3.5-inch diskettes have been around for about 15 years, and they are still found on almost every computer sold today. Solid State: Solid state, at its most basic level, means "no moving parts." Therefore, solid state electronic devices are made up of solid components that do not move. Some examples include computer motherboards and integrated circuits.