E = mc^2 is a relativity equation that was developed by Albert Einstein. It is a common equation in physics, which shows the relationship between the energy and mass of an object.
E stands for energy, measured in joules; m stands for mass, measured in kilograms; and c stands for the speed of light in empty space, measured in meters per second. The equation E=mc^2 means that the energy of the object is equal to the product of the mass and the square of the speed of light. The equation E=mc^2 also can be written as E=m*c*c (E is equal to m times c times c) or spoken as energy equals mass times the speed of light squared.