relativity vs theory of relativity

relativity and theory of relativity both are nouns.

Word	Noun	Adjective	Verb	Adverb
relativity	Yes	No	No	No
theory of relativity	Yes	No	No	No

As nouns, relativity and theory of relativity are synonyms defined as:

relativity and theory of relativity: (physics) the theory that space and time are relative concepts rather than absolute concepts

Other synonyms of relativity include Einstein's theory of relativity, relativity theory.

relativity (noun)	theory of relativity (noun)
the quality of being relative and having significance only in relation to something else	(physics) the theory that space and time are relative concepts rather than absolute concepts
(physics) the theory that space and time are relative concepts rather than absolute concepts