folder vs leaflet

folder and leaflet both are nouns.

Word	Noun	Adjective	Verb	Adverb
folder	Yes	No	No	No
leaflet	Yes	No	No	No

As nouns, folder and leaflet are synonyms defined as:

Other synonyms of folder include booklet, brochure, pamphlet.

folder (noun)	leaflet (noun)
covering that is folded over to protect the contents	a thin triangular flap of a heart valve
a small book usually having a paper cover	a small book usually having a paper cover
	part of a compound leaf