self-assurance vs authority

self-assurance and authority both are nouns.

Word	Noun	Adjective	Verb	Adverb
self-assurance	Yes	No	No	No
authority	Yes	No	No	No

As nouns, self-assurance and authority are synonyms defined as:

self-assurance and authority: freedom from doubt; belief in yourself and your abilities

Other synonyms of self-assurance include assurance, confidence, self-confidence, sureness.

self-assurance (noun)	authority (noun)
freedom from doubt; belief in yourself and your abilities	the power or right to give orders or make decisions
	official permission or approval
	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