burial site vs graveyard

burial site and graveyard both are nouns.

Word	Noun	Adjective	Verb	Adverb
burial site	Yes	No	No	No
graveyard	Yes	No	No	No

As nouns, burial site and graveyard are synonyms defined as:

Other synonyms of burial site include burial ground, burying ground, cemetery, memorial park, necropolis.

burial site (noun)	graveyard (noun)
a tract of land used for burials	a tract of land used for burials