In this lecture I explain why light particles (photons) are referred to as electromagnetic radiation by discussing their wave-like behaviour and how it is associated with their electric and magnetic fields. I also describe the many properties of photons, including wavelength, frequency, and amplitude, and make clear how these particles transfer energy. Finally, I explain how the spectroscopy methods of emission and absorption spectra work, how they can be used to identify elements, and why they are related to the concept of a quantum, and the study of quantum mechanics. Included in this video are concepts such as bight line and dark line spectra, energy levels, ground states, and excited states.