Freud believed that personality develops through 5 psychosexual stages from birth to adulthood. These stages involve the gratification of different erogenous zones: oral, anal, phallic, latency, and genital. Successful completion of each stage results in maturity, while failure can result in fixation causing neuroses. The document provides details on Freud's theories regarding how experiences and conflicts in each stage shape personality traits and relationship patterns in adulthood.