Personality theory is a branch of psychology that seeks to understand the patterns of thoughts, feelings, and behaviors that make individuals unique. It explores how these traits develop and influence a person's interactions with the world. Various models, such as the Big Five personality traits and Myers-Briggs Type Indicator, help categorize and describe different personality types. Researchers in personality theory often study the impact of genetics, environment, and culture on personality development. Theories can be used to predict behavior, improve mental health, and enhance personal relationships. Understanding personality can also aid in career development and team dynamics in workplaces.