Night happens when we can’t see the sun in the sky.
Our planet, Earth, is like a ball, which is also rotating on its axis. It gets light from the sun, which we call sunlight.
When sunlight falls on Earth, it becomes day in the places that receive the sunlight, and for the places that don’t receive sunlight, it becomes night. Have you noticed the sun comes up every morning and goes down every night?
That’s because our Earth is also spinning on its axis, like a top. Because of this spinning, we feel the sun is moving in the sky, very much like how we see the trees moving when we are driving in a car. So, when the sun goes down, it means our side of the Earth is not facing the sun anymore. No sun means no sunlight. Without sunlight, it becomes dark, and we call it night.
At night, we can see the moon and the stars in the sky, which are not visible during the day. They come out to say goodnight and sing their favorite song:
Twinkle, twinkle, little star, how I wonder what you are.
Up above the world so high, like a diamond in the sky.