Problem-Based Learning (PBL) is a learner-centered approach that originated at McMaster University, designed to engage students in real-world problem-solving through cooperative group work. It emphasizes critical thinking, self-directed learning, and teamwork but has disadvantages such as student unpreparedness and the potential for inadequate teacher facilitation. PBL involves structured problem scenarios, assessment methods, and developing essential skills for lifelong learning, particularly in health care professions.