Okay, imagine you and your friends are playing a game outside. You need someone to be the leader to help you win the game. That's what a quarterback is for a football team.
The quarterback is the most important player on the football field and they are like the leader of the team. They get the ball at the beginning of each play and it's up to them to figure out what to do with it.
When they get the ball, they can pass it to one of their teammates or they can run with it themselves. They also have to make sure they don't get tackled by the other team's players.
The quarterback talks to their teammates and tells them what to do on each play. They have to be very smart and make quick decisions during the game.
In short, a quarterback is like the leader and strategist of a football team.