Schubert Calculus is a branch of mathematics that deals with the intersection theory of algebraic varieties, particularly in the context of projective spaces. It provides tools to study the geometric properties of these varieties by analyzing how subspaces intersect with each other. This calculus is named after the composer Franz Schubert, but it is unrelated to music. The main focus of Schubert Calculus is on Schubert classes, which represent the cycles of subspaces in projective space. By using these classes, mathematicians can compute intersection numbers, which reveal important information about the geometry of the varieties involved. This area of study has applications in various fields, including algebraic geometry and mathematical physics.