So, you know how sometimes things can be too loud and it hurts your ears or makes it hard to hear other things? That's called noise.
Now, imagine you're outside playing and you hear lots of different noises. Some might be from cars driving on the road or a noisy machine at a construction site. These are all sounds that aren't supposed to be there and they can be annoying or even harmful to people and animals.
Some people try to make less noise by using quieter machines or driving more slowly, but sometimes there are rules that say you can't make too much noise in certain places. This is because too much noise can disturb wildlife, people who are trying to sleep or just be quiet, and it can even hurt your ears if it's really loud for a long time.
So, it's important to be aware of noise and try to be as quiet as possible so we don't bother others or cause harm to ourselves or the environment.