Maxwell’s equations unified electricity and magnetism in an almost perfect way and predicted that light is an electromagnetic wave. This was a tremendous advancement for physicists on the path toward unification. Many people are aware of Maxwell’s equations and their beauty, but only a few can truly understand these equations because they require calculus and are less straightforward than many other equations. Therefore, What Are Maxwell’s Equations will continue in the style of the “Changweijun Popular Science Series,” using simple language and rigorous logic to thoroughly explain the ins and outs of Maxwell’s equations, making this great set of equations easily comprehensible even to secondary and primary school students without calculus knowledge.