Optics is the study of light and how it interacts with matter as well as other light sources. The three schools of thought on optics are:
Geometric optics basically comes down to ray tracing a Poynting vector as it travels from pne point to another using only reflection and refraction. Wave optics adds diffraction which is purely a wave characteristic, particles cannot diffract. Quantum optics is the only place where we get to use the word photon. Quantum optics will be covered in the Quantum mechanics sections. Here are a few of the more fundamental problems in Optics: