A doctor is a healthcare professional licensed to practice medicine, diagnose illnesses, prescribe treatment, and promote overall health. They undergo extensive education and training, including medical school and residency, to gain expertise in various medical fields. Doctors play a crucial role in patient care, offering preventive care, managing chronic conditions, and performing surgeries. They work in diverse settings, such as hospitals, clinics, and private practices, dedicating their skills and knowledge to improve and save lives.