extent vs area

extent and area both are nouns.

Word	Noun	Adjective	Verb	Adverb
extent	Yes	No	No	No
area	Yes	No	No	No

As nouns, area is a hyponym of extent; that is, area is a word with a more specific, narrower meaning than extent:

extent (noun)	area (noun)
the distance or area or volume over which something extends	a part of a structure having some specific characteristic or function
the point or degree to which something extends	the extent of a 2-dimensional surface enclosed within a boundary
	a part of an animal that has a special function or is supplied by a given artery or nerve
	a subject of study
	a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography)
	a particular environment or walk of life