analog vs similarity

analog and similarity both are nouns.

Word	Noun	Adjective	Verb	Adverb
analog	Yes	Yes	No	No
similarity	Yes	No	No	No

As nouns, similarity is a hypernym of analog; that is, similarity is a word with a broader meaning than analog:

analog (noun)	similarity (noun)
something having the property of being analogous to something else	the quality of being similar
	a Gestalt principle of organization holding that (other things being equal) parts of a stimulus field that are similar to each other tend to be perceived as belonging together as a unit

analog (adjective)	similarity (adjective)
of a circuit or device having an output that is proportional to the input