point of departure vs jumping-off point

point of departure and jumping-off point both are nouns.

Word	Noun	Adjective	Verb	Adverb
point of departure	Yes	No	No	No
jumping-off point	Yes	No	No	No

As nouns, point of departure and jumping-off point are synonyms defined as:

point of departure and jumping-off point: a beginning from which an enterprise is launched

Other synonyms of point of departure include springboard.

point of departure (noun)	jumping-off point (noun)
a beginning from which an enterprise is launched	a beginning from which an enterprise is launched
a place from which an enterprise or expedition is launched