Okay kiddo, so you know how your arm helps you wave hello and pick up your toys? Well, your biceps are the special muscles in your arm that help you do those things.
Have you ever seen someone flex their muscles and make their arm look like a big rock? Well, that's what your biceps do! They sit right at the front of your arm, near your elbow, and help you move your arm when you're picking up things or doing other activities.
Sometimes people work really hard to make their biceps super-strong and look really big. They might go to a special place called a gym and do exercises called "curls" to make their biceps stronger. But even if you don't do any special exercises, your biceps will still be there to help you do things with your arm every day!