Okay kiddo, do you know how sometimes, when you're trying to listen to something really quiet, like a whisper, but then there's a really loud noise that makes it really hard to hear what you were listening to before?
Well, a noise gate is kind of like a magical door that only lets the quiet noises come through and keeps the loud noises out. It's like it puts up a guard at the entrance and only the quiet sounds can pass through.
In music, a noise gate works by only allowing certain sounds to come through while keeping others out. For example, if someone is playing the drums, the noise gate can make sure that only the drum sounds come through while any background noise, like a microphone picking up the sound of someone shuffling their feet, is kept out.
So, just like a door keeps certain things out while allowing others to pass through, a noise gate does the same thing for sounds in music. Pretty cool, huh?