This document provides information about doctors and their profession. It defines what a doctor is and discusses where they work, including hospitals, private practices, and research institutions. It outlines the different types of doctors and their specialties, like cardiologists, neurologists, and psychiatrists. The document also explains what medical studies and training are required to become a doctor. Key instruments used by doctors are also described, such as stethoscopes, thermometers, and scalpels. The impacts of not having doctors are addressed, stating that many people would die from untreated illnesses and injuries.