The führerprinzip is a big, hard-to-say word that means "leader principle" in German. It is a concept that was used by the Nazis, who were a group of very bad people who did really mean things in the past.
The idea behind the führerprinzip is that there is one person who is the boss and makes all the important decisions, and everyone else just follows them without questioning or disagreeing. This person is called the führer, which means "leader" in German.
Imagine you are playing a game with your friends, and one of them is the "leader" or the "boss" of the game. They get to decide all the rules, and everyone else has to follow them. Even if you don't agree with the rules or think they are unfair, you still have to follow them because the leader is in charge.
The führerprinzip is a very bad idea because it takes away people's ability to think for themselves and make their own decisions. It can lead to people doing bad things just because someone in charge told them to, even if they know it is wrong. It's important to always think for yourself and question things that don't seem right, even if someone in charge tells you to do something else.