Trait Theory:Trait theory is a approach to personality that focuses on identifying and measuring individual differences in distinct and relatively stable personality characteristics, or traits, that shape behavior across situations.
Personality Inventory: A personality inventory is a standardized self-report questionnaire designed to measure an individual's standing on various personality traits, often based on a specific personality model like the Five-Factor Model.
Personality Dimensions: The five broad personality dimensions in the Five-Factor Model (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism) represent relatively independent and comprehensive ways of describing an individual's unique personality profile.