internet vs computer network

internet and computer network both are nouns.

Word	Noun	Adjective	Verb	Adverb
internet	Yes	No	No	No
computer network	Yes	No	No	No

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

internet: a computer network consisting of a worldwide network of computer networks that use the TCP/IP network protocols to facilitate data transmission and exchange
computer network: (computer science) a network of computers

internet (noun)	computer network (noun)
a computer network consisting of a worldwide network of computer networks that use the TCP/IP network protocols to facilitate data transmission and exchange	(computer science) a network of computers