Behaviour is the way you act in response to a situation. Many behaviours are learned at a very early age and seem to be ingrained. They may serve a purpose either in the short or long term. Whilst we may not be able to change the way we behave easily we are aware of it.
A habit is something we do repeatedly, often and regularly. We may not be aware we are doing it. Some habits carried to extremes can be harmful.
Hypnotherapy can help review the behaviour and the habit: change the one and eradicate the other.