A resident psychiatrist is a physician who has completed medical school and is in a specialized training program to become a psychiatrist. They work under the supervision of experienced psychiatrists and provide psychiatric evaluations, diagnoses, and treatments to patients with mental health disorders. The training typically lasts four years and includes rotations in various settings such as hospitals, outpatient clinics, and emergency rooms. Upon completion of their training, they can become board-certified in psychiatry and practice independently.