collection vs request

collection and request both are nouns.

Word	Noun	Adjective	Verb	Adverb
collection	Yes	No	No	No
request	Yes	No	Yes	No

As nouns, request is a hypernym of collection; that is, request is a word with a broader meaning than collection:

collection: request for a sum of money
request: a formal message requesting something that is submitted to an authority

Other hypernyms of collection include petition, postulation.

collection (noun)	request (noun)
the act of gathering something together	the verbal act of requesting
a publication containing a variety of works	a formal message requesting something that is submitted to an authority
request for a sum of money
several things grouped together or considered as a whole

collection (verb)	request (verb)
	express the need or desire for
	ask (a person) to do something
	inquire for (information)