So, you know how when you play with your toys, you have a favorite toy that helps you with everything? It's like that, but for grown-ups who work for the government. The Cabinet Secretary is like the grown-up who helps the Prime Minister and the other people in charge of the government.
The Cabinet Secretary's job is to make sure that the people who work for the government are doing their jobs correctly and that everyone is following the rules. They help the Prime Minister with important things like making decisions and giving advice.
The Cabinet Secretary is kind of like the boss of all the other people who work for the government. They make sure everything is running smoothly and people are doing their jobs properly.