A cargo ship is like a big boat that carries a lot of things like toys, food, clothes, and other stuff from one place to another on water. It's like a giant truck for the ocean! Just like how you have to pack your things properly in a bag or suitcase before going on a trip, people who load the cargo ship have to make sure everything is packed nicely and safely so that nothing gets broken or lost during the voyage. Once the ship is loaded, it will start moving on water to deliver all the things to their destination, which might be in a different country or even a different continent!