Computer Science Revision Resource
Optical Storage, Magnetic Storage and Solid State Storage
It is storage that is read by light, typically lasers. The optical refers to the laser. An example is a DVD. An advantage is they can be read only and a disadvantage is the fact that they are easily damaged.
It is a storage that is read and written by magnets. The most common examples include credit card strips and hard drives. A lesser known one is magnetic tape. Some advantages are the fact they are very dense and are relatively cheap for storage capacity. Some disadvantages are that they are very fragile and easily corrupted.