What is the difference between normal behaviour and abnormal behaviour?

 Normal behaviour is behaviour that is within the bounds of what is generally considered to be "normal" or acceptable for a particular culture, society, or situation.

Abnormal behaviour, on the other hand, refers to any type of behaviour that falls outside of the norm and is therefore considered to be abnormal or unexpected. It can refer to anything from mild deviations (e.g., a person who usually eats healthy but occasionally enjoys a junk food binge) to more serious conditions (e.g., a person who has severe obsessive-compulsive disorder).