It can be hard to say what light really is. You are talking about the classical view of light. Descheleschilder's answer is correct. But if you look at a microscopic view of light, you need quantum mechanics.
This is like looking at what air pressure is. In a large scale view (classical), it is a smooth force that air exerts on the walls. But microscopically, it isn't smooth. It is individual air molecules bouncing off the wall. Each molecule gives the wall an individual kick. When you add up lots of these kicks, you get a smooth force. It is really the same explanation, but it looks totally different.
Light is the same. On a microscopic scale, light can be emitted by an individual electron in an atom, and absorbed by another electron in another atom. One atom gives another a kick. When you add up lots of atoms, you can see a smooth force that is described by an electromagnetic field.
An individual atom's worth of light has a name "photon", but that doesn't say what light is. A photon is sort of like a particle and sort of like a wave. For more on that, see my answer to How can a red light photon be different from a blue light photon?.
It can also get confusing if you take a careful look at the classical picture. What kind of thing is an electric field? See my answer to In what medium are non-mechanical waves a disturbance? The aether?