Okay kiddo, so when it comes to the United Kingdom, the person in charge of making important decisions is called the Prime Minister. Think of them like the leader of a team, but for a whole country!
This person is elected by members of Parliament, which is kind of like a big group of grown-ups who make laws and help run the country. The Prime Minister is usually the leader of a political party that has the most members in Parliament.
The Prime Minister's job is to work with other important people, like the Queen (who is kind of like a special grandma for the whole country), to make sure the country is running smoothly. They make plans for things like healthcare, education, and the economy, which is all about money and jobs.
Sometimes, the Prime Minister has to make tough decisions that not everyone will agree with. For example, they might have to decide if the country should go to war or how to handle a big problem like a pandemic.
So, in short, the Prime Minister of the United Kingdom is the leader of the country and works with other important people to make sure the country is doing well.