processing devices:There is a processing device inside all computers called the Central Processing Unit (CPU). The CPU is responsible for taking data inputted by the user and then performing any necessary processing, for example sorting the data, performing calculations on it, saving it to the computer's memory etc
cpu: is the abbreviation for central processing unit. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is the brains of the computer where most calculations take place.
hard drive:a high-capacity, self-contained storage device containing a read-write mechanism plus one or more hard disks, inside a sealed unit. Also called hard disk drive.
rom:Short for read-only memory. Computer hardware that stores programs or data that cannot be added to, modified, or deleted.
external memory devices:Typically refers to storage in an external hard drive or on the Internet. The main "memory" in the computer is the computer's workspace, not its storage facility. See external storage.