property vs extension

property and extension both are nouns.

Word	Noun	Adjective	Verb	Adverb
property	Yes	No	No	No
extension	Yes	No	No	No

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

property (noun)	extension (noun)
any movable articles or objects used on the set of a play or movie	an educational opportunity provided by colleges and universities to people who are not enrolled as regular students
a basic or essential property shared by all members of a class	act of stretching or straightening out a flexed limb
a construct whereby objects or individuals can be distinguished	act of expanding in scope; making more widely available
any area set aside for a particular purpose	an addition that extends a main building
something owned; any tangible or intangible possession that is owned by someone	an addition to the length of something
	an additional telephone set that is connected to the same telephone line
	amount or degree or range to which something extends
	the ability to raise the working leg high in the air
	the most direct or specific meaning of a word or expression; the class of objects that an expression refers to
	a string of characters beginning with a period and followed by one or more letters; the optional second part of a PC computer filename
	the spreading of something (a belief or practice) into new regions
	a mutually agreed delay in the date set for the completion of a job or payment of a debt