Light beams are streams of light that travel in straight lines. They are made up of particles called photons, which move at a speed of about 299,792 kilometers per second in a vacuum. Light beams can be produced by various sources, such as the Sun, light bulbs, and lasers. When light beams encounter different materials, they can be reflected, refracted, or absorbed. For example, when a light beam passes through a prism, it can split into a spectrum of colors. This phenomenon is due to the varying speeds of light in different substances, which causes the light to bend.