Question

e = mc². I don't know anything about that. What is that. Explain in brief.

Answer 1

this is the equation given by albert einstein 
In this expression E=kinetic energy,m=mass of body,c=speed of light
it states that the energy possessed by a body is directly propotional to the square of speed of light as mass is constant.

Answer 2

Einstein's equation showing that Energy is equal to mass times the speed of light squared.The mass energy equivalence given by Einstein is as follows :- E = m c2 Where m= mass that disappears E = energy that appears c = velocity of light in vacuum This is when mass is being converted into energy. Conversely , when an amount of energy E is converted into mass, the mass that appears is m = E/c2. This relation shows that energy can be transformed into energy and vice - versa, i.e., mass can be transformed into energy