TCP vs protocol

TCP and protocol both are nouns.

Word	Noun	Adjective	Verb	Adverb
TCP	Yes	No	No	No
protocol	Yes	No	No	No

As nouns, protocol is a hypernym of TCP; that is, protocol is a word with a broader meaning than TCP:

TCP: a protocol developed for the internet to get data from one network device to another
protocol: (computer science) rules determining the format and transmission of data

Other hypernyms of TCP include communications protocol.

TCP (noun)	protocol (noun)
a protocol developed for the internet to get data from one network device to another	code of correct conduct
	forms of ceremony and etiquette observed by diplomats and heads of state
	(computer science) rules determining the format and transmission of data