Noether's Theorem is a fundamental principle in theoretical physics and mathematics that connects symmetries and conservation laws. Formulated by the mathematician Emmy Noether in 1915, it states that for every continuous symmetry of a physical system, there is a corresponding conservation law. For example, if a system is symmetric in time, it conserves energy; if it is symmetric in space, it conserves momentum. This theorem has profound implications in various fields, including classical mechanics, quantum mechanics, and field theory. It helps physicists understand why certain quantities remain constant over time, providing a deeper insight into the laws governing the universe.