A physicist is a scientist who studies the fundamental principles of matter, energy, and the forces that govern the universe. They explore concepts such as gravity, electricity, and magnetism to understand how the physical world operates. Physicists often conduct experiments and use mathematical models to test their theories and make predictions. There are various branches of physics, including classical mechanics, quantum mechanics, and thermodynamics. Physicists may work in academic settings, research institutions, or industries like engineering and technology. Their findings can lead to advancements in fields such as medicine, energy, and materials science.