<human>:  I have a question about the field of Electro-optics. What is the difference between a photon and an electron?
<bot>: A photon is a quantum of light. An electron is a subatomic particle. A photon is a particle of light, and an electron is a particle of matter. A photon has no mass, and an electron has mass. A photon has no charge, and an electron has charge. A photon has no spin, and an electron has spin.