manners vs behavior

manners and behavior both are nouns.

Word	Noun	Adjective	Verb	Adverb
manners	Yes	No	No	No
behavior	Yes	No	No	No

As nouns, behavior is a hypernym of manners; that is, behavior is a word with a broader meaning than manners:

manners: social deportment
behavior: (behavioral attributes) the way a person behaves toward other people

Other hypernyms of manners include behaviour, conduct, demeanor, demeanour, deportment.

manners (noun)	behavior (noun)
social deportment	manner of acting or controlling yourself
	(psychology) the aggregate of the responses or reactions or movements made by an organism in any situation
	(behavioral attributes) the way a person behaves toward other people
	the action or reaction of something (as a machine or substance) under specified circumstances