Sunlight is the light that comes from the sun, traveling 93 million miles through space to reach Earth. Without sunlight, our planet would be a frozen, lifeless rock. Plants use sunlight to make their food through photosynthesis, animals depend on those plants, and humans depend on both. Sunlight warms the oceans, drives weather patterns, and makes life possible.

When you step outside on a bright day, that warmth on your skin is sunlight. The colors you see exist because sunlight contains all the colors of the rainbow mixed together. When light passes through a prism or raindrops, it splits into red, orange, yellow, green, blue, and violet.

Too much direct sunlight can damage your skin and eyes, which is why people wear sunscreen and sunglasses. But sunlight also helps your body produce vitamin D, which keeps your bones strong. Throughout history, people have understood that sunlight is precious. Ancient Egyptians worshipped the sun god Ra, and even today we talk about someone having a sunny personality when they're cheerful and warm, or we describe a sunlit room as bright and inviting. The word captures both the physical light from our star and the feeling of brightness and life it brings.