computer vs central processing unit

computer and central processing unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
computer	Yes	No	No	No
central processing unit	Yes	No	No	No

computer (noun)	central processing unit (noun)
a machine for performing calculations automatically	(computer science) the part of a computer (a microprocessor chip) that does most of the data processing
an expert at calculation (or at operating calculating machines)