Medical trials are research studies that test new treatments, drugs, or medical devices to determine their safety and effectiveness. Participants, often volunteers, are closely monitored throughout the trial to gather data on how the treatment affects their health. These trials are essential for advancing medical knowledge and improving patient care. There are different phases of medical trials, each with specific goals. Phase I trials focus on safety and dosage, while Phase II trials assess effectiveness. Phase III trials compare the new treatment to standard options, and Phase IV trials monitor long-term effects after approval.