What is the specific explanation of Einstein e = MC2?

What is the specific explanation of Einstein e = MC2?

Mass energy equation, which describes the equivalence between mass and energy and the equivalent relationship. In short, the decrease (increase) of a unit of mass will release (absorb) the energy of square times of the speed of vacuum light. The speed of vacuum light is only a proportional coefficient here, which has nothing to do with the light itself
Mass and energy are unified, they are a form of matter, but we observe them in different ways and angles
The formula points out the conversion relationship between mass and energy. In short, if more than m mass is consumed, so much energy (m times the square of the speed of light) can be produced. For example, in the atomic bomb explosion, the heavy nucleus loses mass in the fission process and produces a lot of energy; more e energy is consumed, So many masses can be generated (e divided by the square of the speed of light) - for example, high-speed particles lose a lot of kinetic energy after colliding, and sometimes new particles are produced, and the total mass is larger than that of the original particles
For another example, electron volt is generally a unit of energy, but sometimes it is also used to express the mass of some basic particles. For example, the mass of the still electron is 0.511 MeV