authority vs permission

authority and permission both are nouns.

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

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

authority (noun)	permission (noun)
the power or right to give orders or make decisions	the act of giving a formal (usually written) authorization
official permission or approval	approval to do something
freedom from doubt; belief in yourself and your abilities
an authoritative written work
an administrative unit of government
an expert whose views are taken as definitive
(usually plural) persons who exercise (administrative) control over others