Attitude is internal, is more about how what you think,or someone's manner or disposition with regard to someone or something, although it often shows on the outside. Behavior is more about what you do.

Often rap artists use these 2 words to mean the same thing Example: That dude has a bad attitude= bad behaviour

behaviour- how someone acts attitude- is more someone's manner or disposition etc, with regard to someone or something. For example if someone is being negative they can have a 'negative attitude'. It can also express an emotion. Someone can have a 'threatening attitude' Also ,,, Attitude is internal, although it often shows on the outside - as behaviour. Behaviour is external - and can be observed.