pamphlet vs leaflet

pamphlet and leaflet both are nouns.

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

As nouns, pamphlet and leaflet are synonyms defined as:

Other synonyms of pamphlet include booklet, brochure, folder.

pamphlet (noun)	leaflet (noun)
a brief treatise on a subject of interest; published in the form of a booklet	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