Could you introduce the rule of football to me?

Sure! Football, also known as soccer, is a team sport played between two teams of eleven players each. The objective of the game is to score goals by kicking the ball into the other team's goal. The team that scores the most goals wins the game.

Each team has a goalkeeper, who is the only player allowed to touch the ball with their hands or arms, within the penalty area surrounding their own goal. The other players, known as field players, are not allowed to touch the ball with their hands or arms, except under specific circumstances.

The game is played on a rectangular field, with a goal at each end. The field players can move the ball by kicking it, using their head, chest, or feet. They can also pass the ball to their teammates by kicking it or hitting it with any part of their body except their hands or arms.

The team that is in possession of the ball is trying to score a goal, while the other team is trying to regain possession of the ball and prevent the other team from scoring. The game is divided into two halves, each lasting 45 minutes, and the team that scores the most goals at the end of the game wins.

There are many rules and regulations in football, but those are the basics. Is there anything else you would like to know?

What's the limitation about the number of players? At least and at most

In a football match, each team is allowed to have a minimum of seven players and a maximum of eleven players on the field at any given time. This includes the goalkeeper and the field players. The team must have at least seven players to be able to start or continue the game, otherwise the game will be abandoned.

The rules of football also allow for a certain number of substitutions, which allow teams to bring new players on to the field to replace players who are injured or tired. The exact number of substitutions allowed varies depending on the competition or league, but it is typically three or five substitutions per game.

Additionally, there is also a limit on the number of players a team can have on its roster, or list of available players. This number can vary depending on the league, but it is typically around 18 to 25 players.