Autopilot is like having a helper in a plane or boat that can help the person who is driving. Imagine you are playing with your toy car and you are holding the remote control. You can move the toy car forward, backwards, left and right by pressing buttons on the remote control. But with autopilot, you can press a special button and the toy car will move on its own without you having to press any buttons.
When a big airplane or boat is traveling, it can be hard work to keep it going in the right direction for a long time. It can be tiring for the person driving and sometimes they might make a mistake. So, they have a special system called autopilot that can take over and keep the plane or boat going in the right direction.
Autopilot uses sensors like cameras and radars to figure out where the plane or boat is going and adjusts the controls to keep it going in the right direction. It can also help the plane or boat maintain the right altitude (height) and speed. This system keeps the driver from getting too tired and helps keep everyone on the plane or boat safe.