protocol vs etiquette

protocol and etiquette both are nouns.

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

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

protocol: forms of ceremony and etiquette observed by diplomats and heads of state
etiquette: rules governing socially acceptable behavior

protocol (noun)	etiquette (noun)
code of correct conduct	rules governing socially acceptable behavior
forms of ceremony and etiquette observed by diplomats and heads of state
(computer science) rules determining the format and transmission of data