This is more intuitive. Now, the third definition is also intuitive. The third definition talks about thermal energy or a kinetic energy of a system. Now, remember, the kinetic energy is the translational energies plus the rotational energies plus the vibrational energies of a system, right? So when we talk about fluids, we talk about mainly translational and rotational energies. And we can formulate this formula here, which basically says translational energy plus rotational energy equals three over two times the constant K times temperature.