land site vs tract

land site and tract both are nouns.

Word	Noun	Adjective	Verb	Adverb
land site	Yes	No	No	No
tract	Yes	No	No	No

As nouns, tract is a hypernym of land site; that is, tract is a word with a broader meaning than land site:

land site: the piece of land on which something is located (or is to be located)
tract: an extended area of land

Other hypernyms of land site include parcel, parcel of land, piece of ground, piece of land.

land site (noun)	tract (noun)
the piece of land on which something is located (or is to be located)	a bundle of myelinated nerve fibers following a path through the brain
	a system of body parts that together serve some particular purpose
	a brief treatise on a subject of interest; published in the form of a booklet
	an extended area of land