"Light is a form of energy, and it's an unusual form of energy light can be considered an electromagnetic wave oscillating electric and magnetic fields, but it's not a wave. The way other waves are like waterways on the ocean. Front are like shore. Those waves can't exist without the water, whereas. Light doesn't need anything in order to propagate. If it's a wave physicists used to ask, what is it that's waving and thing that's waving our electric magnetic fields, which don't actually require anything to exist, which is a good thing for us because the light coming from the sun has to pass through the vacuum about her space. And if it needed some medium in order to propagate, we would be all in the dark here. Wondering why doesn't someone turn on the lights."