integration vs uniting

integration and uniting both are nouns.

Word	Noun	Adjective	Verb	Adverb
integration	Yes	No	No	No
uniting	Yes	No	No	No

As nouns, uniting is a hyponym of integration; that is, uniting is a word with a more specific, narrower meaning than integration:

integration (noun)	uniting (noun)
the action of incorporating a racial or religious group into a community	the act of making or becoming a single unit
the act of combining into an integral whole	the combination of two or more commercial companies
an operation used in the calculus whereby the integral of a function is determined