The Lagrangian is a fancy way of writing an equation to determine the state of a changing system and explain the maximum possible energy the system can maintain. Technically, the Standard Model can be ...

This part of the equation describes how elementary matter particles interact with the weak force. According to this formulation, matter particles come in three generations, each with different masses.

If we plug the Lagrangian of a system into the Euler-Lagrange equation and the result will be equations describing how that system will move and change over time.