Okay kiddo, have you ever heard of the sun? It's that big, bright ball in the sky that makes everything warm and gives us light. The sun is nice to us, but sometimes it can be too strong and hurt our skin.
That's why we use something called the UV Index to measure how strong the sun's rays are. UV stands for Ultraviolet, which is a type of light that the sun gives off.
The UV Index is a scale from 0 to 11 and tells us how much UV radiation is coming from the sun at a particular time and place. When the UV Index is low like 0 or 1, it means there isn't much UV radiation and we don't have to worry about it hurting us. But when the UV Index is high like 8 or 9, we need to be careful because the UV radiation can damage our skin and eyes.
So remember, kiddo, when you hear someone talking about the UV Index, it's just a way to measure how strong the sun's rays are and how careful we need to be when we're outside. Always wear sunscreen and sunglasses to protect yourself from those strong rays!