An intermodal container is like a big box made out of metal that can be loaded onto different types of transportation, like ships, trains, and trucks. It looks like a rectangle and has a door on one side that can be opened and closed. The container can be filled with all sorts of things, like toys, clothes, electronics, and food.
When a container is loaded onto a ship, it travels across the ocean to another country. When it arrives, it can be lifted off the ship with a crane and put onto a train or a truck. Then it travels to various places like warehouses, factories, and stores. The container is very useful because it keeps everything inside safe and dry, and it can be easily moved from one type of transportation to another without having to take everything out and put it back in.
Think of the intermodal container like a big magic box that can travel all over the world and take anything you want with it, as long as it fits inside!