consent vs permission

consent and permission both are nouns.

Word	Noun	Adjective	Verb	Adverb
consent	Yes	No	Yes	No
permission	Yes	No	No	No

As nouns, permission is a hypernym of consent; that is, permission is a word with a broader meaning than consent:

consent (noun)	permission (noun)
permission for something to happen	the act of giving a formal (usually written) authorization
	approval to do something

consent (verb)	permission (verb)
give an affirmative reply to; respond favorably to