This book is an in-depth textbook introducing and covering all topics related to the fact that light is a transverse electromagnetic wave. It begins with a discussion of the history of Maxwell’s equations, from which the wave properties of light were first deduced, and then moves into the fundamentals of electromagnetic waves, such as the polarization of light, energy and momentum conservation, and basic solutions of Maxwell’s equations. From there, it will move into more practical topics: light propagation in matter of various types, light propagation through interfaces, light propagation in waveguides (like fiber optic cables), and light scattering.