An eyepiece is like a little lens that you look through to see objects that are far away, like stars, planets or even birds! It helps you zoom in and get a closer look at things that are really far away. Think of it like a tiny telescope that you can hold in your hand. When you look through an eyepiece, the object you're looking at appears bigger and more detailed than if you were just looking at it with your own eyes. So, if you want to see things that are far away, like planets or stars, you'll need an eyepiece to help you see them up close.