Okay kiddo, imagine you want to go visit your friend who lives far away, across a big body of water. You can't walk or drive there, so you have to take a special train that goes through a really long tunnel under the water. This tunnel is called the Eurotunnel.
Now, the Eurotunnel is so long that you can't just walk through it like you would a regular tunnel. That's where the Eurotunnel Shuttle comes in. The shuttle is a special train that carries people and their cars through the tunnel.
When you want to take the shuttle, you drive your car onto a big train car that can hold lots of cars. Then, you get out of your car and go up to the passenger part of the train. There, you can sit in your seat and watch the view go by as the shuttle travels through the tunnel.
It's really cool, because you get to travel under the water and see things you can't see anywhere else. And before you know it, you'll be on the other side of the water, ready to visit your friend!