cemetery vs burial site

cemetery and burial site both are nouns.

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

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

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

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