Sometimes, when a part of the body like an arm or a leg gets really, really hurt or sick, doctors might need to remove it to help the rest of the body stay healthy. It’s like when you have a toy with a broken wheel that can’t be fixed, you might need to take that wheel off so the toy can still work properly.
Think of your body as a tree. If one of the branches is badly damaged by a storm, it might not grow anymore and could make the rest of the tree sick. So, gardeners might need to cut off the bad branch to keep the tree strong and healthy.
Another way to understand it is by thinking about a puzzle. If one piece is torn or doesn’t fit anymore, you might need to take it out so the rest of the puzzle looks nice and complete. Doctors do something similar when they amputate; they make sure the body can work as best as it can, even if a part is missing.