translation vs subtitle

translation and subtitle both are nouns.

Word	Noun	Adjective	Verb	Adverb
translation	Yes	No	No	No
subtitle	Yes	No	Yes	No

As nouns, subtitle is a hyponym of translation; that is, subtitle is a word with a more specific, narrower meaning than translation:

translation: a written communication in a second language having the same meaning as the written communication in a first language
subtitle: translation of foreign dialogue of a movie or TV program; usually displayed at the bottom of the screen

Other hyponyms of translation include mistranslation, crib, pony, trot, retroversion, caption, supertitle, surtitle.

translation (noun)	subtitle (noun)
the act of uniform movement	secondary or explanatory title
the act of changing in form or shape or appearance	translation of foreign dialogue of a movie or TV program; usually displayed at the bottom of the screen
a written communication in a second language having the same meaning as the written communication in a first language
rewording something in less technical terminology
a uniform movement without rotation
(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm
(mathematics) a transformation in which the origin of the coordinate system is moved to another position but the direction of each axis remains the same

translation (verb)	subtitle (verb)
	supply (a movie) with subtitles