language unit vs component

language unit and component both are nouns.

Word	Noun	Adjective	Verb	Adverb
language unit	Yes	No	No	No
component	Yes	No	No	No

As nouns, component is a hypernym of language unit; that is, component is a word with a broader meaning than language unit:

language unit: one of the natural units into which linguistic messages can be analyzed
component: something determined in relation to something that includes it

Other hypernyms of language unit include component part, constituent, part, portion.

language unit (noun)	component (noun)
one of the natural units into which linguistic messages can be analyzed	an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system
	an abstract part of something
	something determined in relation to something that includes it