If you mean in the equation E=mc2, the "m" stands for mass.
E = mc2 This is Albert Einstein's famous Relativity equation: Which means that in a vacuum the Energy is equal to the Mass times the Speed of light squared.
E = mc2 is Albert Einstein's famous equation
The famous equation E=MC2 was devised by one Albert Einstein. The equation means that the energy released when you destroy something is equal to the mass of that something times the speed of light squared, which is quite a lot.
e=mc2
Without an equality sign E mc2 cannot be classed as an equation
This can be answered in two ways... If you're talking about Einstein's equation, then E=MC2. If you are wondering what E means, it stands for energy, so Einstein's equation means, "energy is equal to mass times the speed of light squared'.
E = mc2
E=MC2
E=mc2
E=mc2
Albert Einstein.Except that the equation was e = mc2