personal manner vs demeanour

personal manner and demeanour both are nouns.

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

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

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

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

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