personal manner vs behaviour

personal manner and behaviour both are nouns.

Word	Noun	Adjective	Verb	Adverb
personal manner	Yes	No	No	No
behaviour	Yes	No	No	No

As nouns, behaviour is a hypernym of personal manner; that is, behaviour is a word with a broader meaning than personal manner:

personal manner: a way of acting or behaving
behaviour: (behavioral attributes) the way a person behaves toward other people

Other hypernyms of personal manner include behavior, conduct, demeanor, demeanour, deportment.

personal manner (noun)	behaviour (noun)
a way of acting or behaving	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