Port of entry

Alright kiddo, imagine you're going to a big amusement park. Now, just like how there is only one gate where people can enter the amusement park, there are specific places where people and things can come into a country. These places are called "ports of entry".

At these ports, there are special people called "border officers" who check everyone and everything that wants to enter the country. They make sure that no dangerous things or people are coming in, and that everything and everyone has the right paperwork to enter.

So, just like how you need a ticket to enter the amusement park, people and things need certain documents to enter a country. And just like how the security guards at the amusement park check your bag, the border officers at the port of entry check everyone's passport and other important documents.

That's basically what a "port of entry" is, a place where people and things enter a country after being checked by special officers.