Lagrangian Mechanics is a reformulation of classical mechanics that focuses on the dynamics of a system using the principle of least action. It uses a function called the Lagrangian, which is defined as the difference between the kinetic and potential energy of a system. This approach simplifies the analysis of complex systems, especially when dealing with constraints. In Lagrangian Mechanics, the equations of motion are derived from the Euler-Lagrange equation. This method allows for a more systematic way to handle problems in physics, making it particularly useful in fields like theoretical physics and engineering. It provides a powerful framework for understanding the motion of particles and rigid bodies.