Theoretical Chemistry is a branch of chemistry that uses mathematical models and computer simulations to understand chemical systems and predict their behavior. It combines principles from physics and mathematics to explain how molecules interact, react, and change over time. This field helps chemists gain insights into complex processes that may be difficult to observe directly in experiments. Researchers in Theoretical Chemistry often develop theories and computational methods to study various phenomena, such as quantum mechanics and thermodynamics. By applying these theories, they can explore new materials, design drugs, and understand biological processes at the molecular level, ultimately advancing both science and technology.