campsite vs encampment

campsite and encampment both are nouns.

Word	Noun	Adjective	Verb	Adverb
campsite	Yes	No	No	No
encampment	Yes	No	No	No

As nouns, campsite and encampment are synonyms defined as:

campsite and encampment: a site where people on holiday can pitch a tent

Other synonyms of campsite include bivouac, campground, camping area, camping ground, camping site.

campsite (noun)	encampment (noun)
a site where people on holiday can pitch a tent	the act of encamping and living in tents in a camp
	temporary living quarters specially built by the army for soldiers
	a site where people on holiday can pitch a tent