display case vs showcase

display case and showcase both are nouns.

Word	Noun	Adjective	Verb	Adverb
display case	Yes	No	No	No
showcase	Yes	No	No	No

As nouns, display case and showcase are synonyms defined as:

display case and showcase: a glass container used to store and display items in a shop or museum or home

Other synonyms of display case include case, vitrine.

display case (noun)	showcase (noun)
a glass container used to store and display items in a shop or museum or home	a glass container used to store and display items in a shop or museum or home
	a setting in which something can be displayed to best effect