selection vs potpourri

selection and potpourri both are nouns.

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

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

Other hypernyms of selection include assortment, miscellanea, miscellany, mixed bag, mixture, motley, salmagundi, smorgasbord, variety.

selection (noun)	potpourri (noun)
the act of choosing or selecting	a jar of mixed flower petals and spices used as perfume
the person or thing chosen or selected	a musical composition consisting of a series of songs or other musical pieces from various sources
a passage selected from a larger work	a collection containing a variety of sorts of things
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