all the parts
A random-access memory device allows data items to be read and written in roughly the same amount of time regardless of the order in which data items are accessed. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement delays.
hard drive disk
A hard disk drive (HDD)[b] is a data storage device used for storing and retrieving digital information using rapidly rotating disks (platters) coated with magnetic material
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output operations specified by the instructions. The term has been used in the computer industry at least since the early 1960s.
The Imitation Game - clip #4 - Alan Turing is interrogated