Refraction when light waves pass through different densities, they change speed. This causes the angle it comes at to change. light normally travels in straight lines until they are in contact with another material.
Reflection
Reflection is when light bounces off an object. if the object is shinny (like glass, water or polished metal) the light willl reflect at the same angle as it hits the surface.
Spectrum of colours The visible light spectrum is part of the electromagnetic spectrum and is the only part we can see because light can behave like a wave as well as a particle, it can bounce of object for example, to see white light split into colours, you can put it through a small gap.