The figure shows the “Standard Model Lagrangian” equation in particle physics. In the second picture is the simplest form of it. The standard model of particle physics is one of the most successful theories about how our universe works, and also describes the basic interactions between elementary particles.
I recently read an article that explains each term in this equation very simply, if you are a person who loves physics you are sure to enjoy it. Those interested can read and follow the link below! (Read for free (Open access article))
Woithe, J., Wiener, G. J., & Van der Veken, F. F. (2017). Let’s have a coffee with the Standard Model of particle physics !. Physics Education, 52 (3), 034001.