stamp collection vs philately

stamp collection and philately both are nouns.

Word	Noun	Adjective	Verb	Adverb
stamp collection	Yes	No	No	No
philately	Yes	No	No	No

As nouns, stamp collection and philately are synonyms defined as:

stamp collection and philately: the collection and study of postage stamps

Other synonyms of stamp collection include stamp collecting.

stamp collection (noun)	philately (noun)
the collection and study of postage stamps	the collection and study of postage stamps
a collection of stamps