CPU vs computer hardware

CPU and computer hardware both are nouns.

Word	Noun	Adjective	Verb	Adverb
CPU	Yes	No	No	No
computer hardware	Yes	No	No	No

As nouns, computer hardware is a hypernym of CPU; that is, computer hardware is a word with a broader meaning than CPU:

CPU: (computer science) the part of a computer (a microprocessor chip) that does most of the data processing
computer hardware: (computer science) the mechanical, magnetic, electronic, and electrical components making up a computer system

Other hypernyms of CPU include electronic equipment, hardware.

CPU (noun)	computer hardware (noun)
(computer science) the part of a computer (a microprocessor chip) that does most of the data processing	(computer science) the mechanical, magnetic, electronic, and electrical components making up a computer system