postulant vs requester

postulant and requester both are nouns.

Word	Noun	Adjective	Verb	Adverb
postulant	Yes	No	No	No
requester	Yes	No	No	No

As nouns, requester is a hypernym of postulant; that is, requester is a word with a broader meaning than postulant:

postulant: one submitting a request or application especially one seeking admission into a religious order
requester: one praying humbly for something

Other hypernyms of postulant include petitioner, suppliant, supplicant.

postulant (noun)	requester (noun)
one submitting a request or application especially one seeking admission into a religious order	one praying humbly for something