coalition vs alliance

coalition and alliance both are nouns.

Word	Noun	Adjective	Verb	Adverb
coalition	Yes	No	No	No
alliance	Yes	No	No	No

As nouns, coalition and alliance are synonyms defined as:

coalition and alliance: an organization of people (or countries) involved in a pact or treaty

Other synonyms of coalition include alignment, alinement.

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

Other hyponyms of coalition include confederation, federalisation, federalization.

coalition (noun)	alliance (noun)
the union of diverse things into one body or form or group; the growing together of parts	the act of forming an alliance or confederation
an organization of people (or countries) involved in a pact or treaty	a formal agreement establishing an association or alliance between nations or other groups to achieve a particular aim
the state of being combined into one body	an organization of people (or countries) involved in a pact or treaty
	a connection based on kinship or marriage or common interest
	the state of being allied or confederated