Okay kiddo, have you ever been to the doctor when you got sick or hurt? And do you know how much it costs to go to the doctor?
Well, some countries have something called a National Health Service or NHS. It means that everyone who lives in the country can go to the doctor or hospital for free, no matter how much money they make or whether they have insurance.
The government pays for the NHS with taxes that everyone pays, and that way they can take care of everyone's health. That means everyone can get treated for illnesses or injuries, get check-ups to make sure they're healthy, and get medicine they need.
It also means that people don't have to worry about how much it costs to go see a doctor or get medicine, and they can focus on getting better.
So basically, the National Health Service is like a big doctor's office or hospital that everyone can go to, and the government pays for it so everyone can be healthy without worrying about money.