Medicinal drugs are substances used to diagnose, treat, or prevent diseases and medical conditions. They can be derived from natural sources, such as plants and minerals, or synthesized in laboratories. These drugs work by interacting with the body's systems to alleviate symptoms, cure illnesses, or improve overall health. There are various types of medicinal drugs, including antibiotics for fighting infections, analgesics for pain relief, and vaccines for preventing diseases. Each drug has specific uses, benefits, and potential side effects, making it essential for healthcare professionals to prescribe them appropriately for patient safety and effectiveness.