touch on vs alter

touch on and alter both are verbs.

Word	Noun	Adjective	Verb	Adverb
touch on	No	No	Yes	No
alter	No	No	Yes	No

As verbs, alter is a hypernym of touch on; that is, alter is a word with a broader meaning than touch on:

Other hypernyms of touch on include change, modify.

touch on (verb)	alter (verb)
restore by replacing a part or putting together what is torn or broken	remove the ovaries of
have an effect upon	become different in some particular way, without permanently losing one's or its former characteristics or essence
refer to or discuss briefly	cause to change; make different; cause a transformation
be relevant to	insert words into texts, often falsifying it thereby
	make an alteration to