Mori Theory, developed by Japanese mathematician Shinichi Mori in the 1980s, is a framework in algebraic geometry that studies the properties of algebraic varieties. It focuses on the classification of these varieties through the concept of mori contractions, which are morphisms that simplify the structure of a variety while preserving essential features. The theory is particularly significant in understanding the geometry of higher-dimensional spaces. It provides tools for analyzing the relationships between different varieties and their birational equivalences, contributing to the broader field of birational geometry. Mori Theory has applications in various areas, including string theory and moduli spaces.