unchangeable vs unalterable

unchangeable and unalterable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unchangeable	No	Yes	No	No
unalterable	No	Yes	No	No

unchangeable (adjective)	unalterable (adjective)
not changeable or subject to change	not capable of being changed or altered
	of a sentence; that cannot be changed
	remaining the same for indefinitely long times