Okay kiddo, have you ever heard of the word "immigration"? It's when people move from one country to another. Sometimes, when people move to a new country, they need to pay some extra money for something called a "health surcharge".
Now, a health surcharge is like a special payment you make to the government to help cover the cost of healthcare. This is important because if someone were to get sick or hurt in a new country, they would need to go to the doctor or to the hospital. And when they do that, they need to pay money for the doctor's time, the medicine they use, and any machines they use to check how their body is doing.
So the immigration health surcharge is a way for people who move to a new country to help pay for any healthcare they might need while they're living there. It's like a little extra fee that they pay to make sure they can get the medical help they need.