Alright kiddo! Have you ever heard of a place called Tarbert? It's actually a town in Scotland, but it's also the name of a really important thing called a "Tariff Barrier" or "Tarbert" for short.
Now, let's say you have some yummy chocolate that you want to sell to people in another country. When you try to sell it, you find out that there is a special tax or fee called a "tariff" that you have to pay in order to bring your chocolate into that country. This can make your chocolate more expensive and less people might want to buy it.
So, a Tarbert is basically a wall made out of tariffs that can stop things from moving freely between countries. It's like building a big, tall fence between your house and your neighbor's house. You can still talk to your neighbor, but it's harder to share things like toys or cookies.
Governments use Tarberts to control the flow of goods and money between countries. Sometimes they use them to help protect businesses in their country from competition from other countries, but sometimes they can create problems and make things more expensive for everyone.
So remember, Tarberts are like big walls made out of taxes that can stop things from moving between countries. They can be good or bad depending on how they are used.