revitalisation vs improvement

revitalisation and improvement both are nouns.

Word	Noun	Adjective	Verb	Adverb
revitalisation	Yes	No	No	No
improvement	Yes	No	No	No

As nouns, improvement is a hypernym of revitalisation; that is, improvement is a word with a broader meaning than revitalisation:

Other hypernyms of revitalisation include advance, betterment.

revitalisation (noun)	improvement (noun)
bringing again into activity and prominence	the act of improving something
	a change for the better; progress in development
	a condition superior to an earlier condition