redevelopment vs improvement

redevelopment and improvement both are nouns.

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

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

redevelopment (noun)	improvement (noun)
the act of improving by renewing and restoring	the act of improving something
	a change for the better; progress in development
	a condition superior to an earlier condition