The equation E=mc2 was formulated by the great physicist Albert Einstein. Matter contains energy. To quantify this relationship, equation E=mc2 had been formulated. It states the correlation of energy and mass (the sum total of matter that forms a body or an object).
Energy is denoted by E and its unit of measurement is Joule. Mass is denoted by m and its unit of measurement is kilograms or grams. c is the speed of light.
When mass of an object is multiplied by the square of speed of light, then we get the energy contained within to object.