jerking off vs masturbation

jerking off and masturbation both are nouns.

Word	Noun	Adjective	Verb	Adverb
jerking off	Yes	No	No	No
masturbation	Yes	No	No	No

As nouns, masturbation is a hypernym of jerking off; that is, masturbation is a word with a broader meaning than jerking off:

jerking off: slang for masturbation
masturbation: manual stimulation of the genital organs (of yourself or another) for sexual pleasure

Other hypernyms of jerking off include onanism.

jerking off (noun)	masturbation (noun)
slang for masturbation	manual stimulation of the genital organs (of yourself or another) for sexual pleasure