E=mc^2 is a version of Einstein's famous relativity equation. Specifically, it means that energy is equal to mass multiplied by the speed of light squared. While seemingly simple, this equation has many profound implications, chief among them being that matter and energy are actually the same stuff. Pure energy in the form of motion can be converted into matter, through the creation of a particle, which has mass. However, as the equation implies, it takes a huge amount of energy to create a tiny bit of mass.