A reach stacker is like a big robot that helps move really heavy containers on ships, trucks, and trains. Imagine you have a toy truck, and you want to stack some blocks on top of it. You might be able to stack one or two blocks, but if you try to stack too many, it will fall over.
Now imagine you have a reach stacker, which is much bigger than your toy truck. It has long arms that can reach out and grab the container, no matter how big and heavy it is. The reach stacker can pick up the container and move it onto another truck, train, or ship.
The reach stacker is controlled by a driver in a special seat, kind of like a race car driver. The driver uses buttons and levers to make the reach stacker move forwards, backwards, and up and down. It's important for the driver to be very careful, because the container is really heavy and could hurt someone if it falls.
Overall, a reach stacker is like a giant, helpful robot that moves heavy things around the world!