Personality refers to individual differences in representative patterns of thoughtful, feeling and performing. The study of personality focuses on two broad areas: One comprehends individual differences in particular personality characteristics, such as sociability or irritability. The other understands how the various parts of a person come together as a whole. A set of qualities which make a person(or thing) distinct from another. An assumed role or manner of behavior. Different behavior theorists present their own definitions of the word based on their theoretical positions.