authority vs command

authority and command both are nouns.

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

As nouns, command is a hyponym of authority; that is, command is a word with a more specific, narrower meaning than authority:

Other hyponyms of authority include power of appointment, carte blanche, imperium, lordship, muscle, sovereignty.

authority (noun)	command (noun)
the power or right to give orders or make decisions	the power or authority to command
official permission or approval	availability for use
freedom from doubt; belief in yourself and your abilities	great skillfulness and knowledge of some subject or activity
an authoritative written work	an authoritative direction or instruction to do something
an administrative unit of government	(computer science) a line of code written as part of a computer program
an expert whose views are taken as definitive	a military unit or region under the control of a single officer
(usually plural) persons who exercise (administrative) control over others	a position of highest authority

authority (verb)	command (verb)
	make someone do something
	be in command of
	demand as one's due
	exercise authoritative control or power over
	look down on