The word light has several related meanings:

1. The brightness that lets us see, coming from the sun, fire, lamps, or other sources. Without light, everything would be completely dark. Light travels incredibly fast (about 186,000 miles per second) and makes vision possible. When you flip a switch, electric current heats a filament or excites gases to produce light.
2. Not heavy or weighing very little. A feather is light, while a bowling ball is heavy. You might pack a light backpack for a short hike, bringing just water and snacks instead of everything you own. Athletes benefit from light equipment that doesn't slow them down.
3. Gentle or not intense. A light touch barely makes contact, like petting a butterfly. A light rain sprinkles rather than pours. You might read a light book when you want something fun and easy rather than serious and challenging. A light punishment is less severe than a harsh one.
4. Pale in color. Light blue is closer to white than dark blue. Someone with light skin or light hair has less pigment than someone with dark skin or dark hair.

These meanings connect through the idea of something not overwhelming, whether it's the gentle presence of brightness, minimal weight, softness of touch, or paleness of color.