Knee-high boots are like shoes that go way up your leg! They're usually made of a material that's pretty strong so your feet don't hurt if you walk a long way. The part at the bottom of the boots is called the sole, and it's made of rubber so it won't slip when you're walking on wet or slippery floors.
The top of the boots goes all the way up to your knees, which is where your legs bend when you walk. The part of the boots that goes around your leg is called the shaft, and it's usually pretty straight and has a zipper or buttons that help you put the boots on and take them off.
Knee-high boots are great to wear with a lot of different outfits, like dresses, skirts, or even pants. They can keep your legs warm when it's chilly outside, or they can look really cool when it's not so chilly!
But remember, even though knee-high boots can look really awesome, they're still just shoes, which means you should be careful when you're wearing them so you don't trip or fall. But if you do, don't worry too much - just get back up and keep walking!