canvasser vs requester

canvasser and requester both are nouns.

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

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

Other hypernyms of canvasser include petitioner, suppliant, supplicant.

canvasser (noun)	requester (noun)
someone who conducts surveys of public opinion	one praying humbly for something
someone who examines votes at an election
a petitioner who solicits contributions or trade or votes
a person who takes or counts votes