touch on vs relate

touch on and relate both are verbs.

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

As verbs, touch on and relate are synonyms defined as:

Other synonyms of touch on include bear on, come to, concern, have to do with, pertain, refer, touch.

touch on (verb)	relate (verb)
restore by replacing a part or putting together what is torn or broken	make a logical or causal connection
have an effect upon	give an account of; narrate
refer to or discuss briefly	have or establish a relationship to
be relevant to	be relevant to
	be in a relationship with