selection vs decision making

selection and decision making both are nouns.

Word	Noun	Adjective	Verb	Adverb
selection	Yes	No	No	No
decision making	Yes	No	No	No

As nouns, decision making is a hypernym of selection; that is, decision making is a word with a broader meaning than selection:

Other hypernyms of selection include deciding.

selection (noun)	decision making (noun)
the act of choosing or selecting	the cognitive process of reaching a decision
the person or thing chosen or selected
a passage selected from a larger work
an assortment of things from which a choice can be made
a natural process resulting in the evolution of organisms best adapted to the environment