litigation vs legal proceeding

litigation and legal proceeding both are nouns.

Word	Noun	Adjective	Verb	Adverb
litigation	Yes	No	No	No
legal proceeding	Yes	No	No	No

As nouns, legal proceeding is a hypernym of litigation; that is, legal proceeding is a word with a broader meaning than litigation:

litigation: a legal proceeding in a court; a judicial contest to determine and enforce legal rights
legal proceeding: (law) the institution of a sequence of steps by which legal judgments are invoked

Other hypernyms of litigation include proceeding, proceedings.

litigation (noun)	legal proceeding (noun)
a legal proceeding in a court; a judicial contest to determine and enforce legal rights	(law) the institution of a sequence of steps by which legal judgments are invoked