Scientists have 2 ways to think about light: it can be a wave or a particle called a photon. It took a long time to discover that both were true. For some time there had been a debate between supporters of each point of view. Nobody - or everybody - won the argument; light is both wave and particle.
This light that we see is just one small chunk of light which is made by stars. We often call this small range of light, optical, or visible light.
The full range of light is called the electromagnetic spectrum.