James Clerk Maxwell was a Scottish physicist who is best known for his work in formulating the classical theory of electromagnetic radiation. He developed a set of equations, known as Maxwell's equations, which describe the behavior of electric and magnetic fields and their interactions with matter. His work laid the foundation for modern physics and led to the development of technologies such as radio, television, and radar. Maxwell's contributions to the field of electromagnetism are considered to be among the most significant in the history of science.