This lecture covers the fundamentals of Maxwell's equations in vacuum, wave equations, and electromagnetic (EM) waves. It delves into the properties of EM waves, the EM spectrum, and the observation of light oscillations. The instructor discusses the speed of light, wave propagation, and the energy levels associated with different parts of the EM spectrum. Various examples are provided to illustrate the challenges in observing light oscillations at different timescales, from picoseconds to attoseconds.