Hello! Do you want to know why we have day and night? It's because our Earth is like a big round ball that spins around and around. Watch how Earth turns!
The Sun is like a very big light bulb in the sky. It shines bright light on our Earth. But the Sun can only shine on one side of Earth at a time, just like a flashlight!
When the Sun shines on one side of Earth, that side has day time and it's bright! The other side is dark and has night time. As Earth spins, day and night take turns! When it's day for you, it's night for kids on the other side of Earth!