Light starts at a light source and travels through space until it hits an object. When light hits an object, some of the light is absorbed and some of the light is reflected. The reflected light is what we see when we look at an object.
The distance between the light source and the object is called the length of the beam of light. The width of the beam of light is determined by the size of the light source.
Beams of light can also be created by lasers. Lasers produce very narrow beams of light that can travel for long distances without being absorbed or scattered.
