This document provides an overview of theories of personality, including type theories, trait theories, and Eysenck's three-factor model of personality. It discusses several influential theorists who developed typologies of personality based on physical characteristics or temperaments, such as Hippocrates, Kretschmer, Spranger, Sheldon, Jung, and Freud. It also summarizes Allport and Cattell's trait theories and classifications of traits. Finally, it explains Eysenck's three dimensions of personality - introversion-extraversion, neuroticism-stability, and psychoticism - and their associated characteristics. The document aims to outline the major theories that have been developed to study personality as a relatively stable set of characteristics