orangutan vs great ape

orangutan and great ape both are nouns.

Word	Noun	Adjective	Verb	Adverb
orangutan	Yes	No	No	No
great ape	Yes	No	No	No

As nouns, great ape is a hypernym of orangutan; that is, great ape is a word with a broader meaning than orangutan:

orangutan: large long-armed ape of Borneo and Sumatra having arboreal habits
great ape: any of the large anthropoid apes of the family Pongidae

Other hypernyms of orangutan include pongid.

orangutan (noun)	great ape (noun)
large long-armed ape of Borneo and Sumatra having arboreal habits	any of the large anthropoid apes of the family Pongidae