Light, or Visible Light, commonly refers to electromagnetic radiation that can be detected by the human eye. The study of light, known as optics, is an important research area in modern physics. On Earth, it comes from anything warm, including living things, like us! Visible light is a very narrow region of the spectrum. Hot objects like stars emit a lot of visible light. Some sources you encounter every day are the sun, light bulbs, and microwaves. The light sources that Stellar Net offers fall into three categories: lasers, lamps, and LEDs.