A theorem is a statement or proposition that has been proven to be true based on previously established statements, such as axioms and other theorems. The process of proving a theorem involves logical reasoning and mathematical techniques, ensuring that the conclusion follows necessarily from the premises. Theorems are fundamental in various fields of mathematics, providing a foundation for further exploration and discovery. In mathematics, famous theorems include Pythagorean Theorem, which relates the sides of a right triangle, and Fermat's Last Theorem, which states that no three positive integers can satisfy a certain equation. Theorems play a crucial role in advancing knowledge and understanding in mathematics and related disciplines.