Psychotherapy is the treatment of emotional or related bodily problems through psychological means such as verbal and emotional communication. Its objectives include removing or modifying existing symptoms, changing disturbed behavior patterns, and promoting positive personality growth. Psychotherapy can be scientific or an art. As a science, it focuses on problems and treatment using techniques like interpretation and behavior modification. As an art, it focuses on prevention using techniques like emotional support and reassurance. There are different types of psychotherapy based on depth of probing into the unconscious mind and number of patients treated, as well as purpose and techniques used. Common techniques include ventilation, abreaction, reassurance, explanation, suggestion, reinforcement, recreation, work as therapy, and relaxation.