Explanation:

- In football, cards are shown to indicate a player's misconduct.

- Yellow

- Yellow card is used to warn a player.

- It serves as a warning for unsporting behavior or repeated offenses.

- Red

- Red card signifies a serious offense.

- Results in the player's immediate ejection from the game.

- Blue

- Blue cards are not used in traditional football rules.

- Green

- Green cards are generally not used in professional football.