An earplug is an object that you put in your ear to help make things quieter. Imagine you are trying to sleep while your big brother is playing music really loudly in the next room. If you put an earplug in your ear it can help block out some of that noise so you can sleep better.
Earplugs can be made out of different materials like foam, silicone or wax. They all work in the same way by making a barrier between your ear and the sounds around you.
When you put an earplug in your ear, it should fit snugly but not too tight. That way it can block out sound, but also be comfortable. Some earplugs come with a string or handle to make it easier to take them out.
It's important to remember to only use earplugs when you really need them, like if it's too noisy to sleep or if you're going to a loud concert. If you wear earplugs all the time, it can lead to other problems like ear infections. It's also important to never push the earplug too far into your ear or it can hurt your ear.
So in short, earplugs are like little helpers that can make things quieter, but you should only use them when you really need them and always be careful when putting them in your ear.