Question

e=mc2 explain in detail

Answer 1

E= Energy
M = Mass
C= Velocity of light in vaccum or air

Answer 2

It's not like this.
The original equation (can even be seen in the genuine papers of his work) was 
$m= \frac{E}{c^{2} }$
That is the very small amount of mass of a system due to presence of some kinetic energy.

In a system or a body, its original mass is the sum of its rest mass and that small mass due to the kinetic energy or binding energy, $m= \frac{E}{c^{2} }$