selection vs casting

selection and casting both are nouns.

Word	Noun	Adjective	Verb	Adverb
selection	Yes	No	No	No
casting	Yes	No	No	No

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

selection (noun)	casting (noun)
the act of choosing or selecting	the act of creating something by casting it in a mold
the person or thing chosen or selected	the act of throwing a fishing line out over the water by means of a rod and reel
a passage selected from a larger work	the choice of actors to play particular roles in a play or movie
an assortment of things from which a choice can be made	object formed by a mold
a natural process resulting in the evolution of organisms best adapted to the environment