Crowning King in Checkers
When a checker achieves the opponent's edge of the board (called the "king's row") it is crowned with another checker. This signifies that the checker has been made a king. The king now gains an added ability to move backward. The king may now also jump in either direction or even in both directions in one turn (if he makes multiple jumps).
A similar idea in the game of chess occurs when a pawn reaches the opponent's end of the board it becomes a queen. There is a practical reason for these piece promotions. Without it, a piece which can only move in one direction becomes worthless. Interestingly enough it also has some social significance in that it signifies that royalty and power should not be simply endowed at birth. Nobility is something that can be and should be earned.
If the player gets an uncrowned checker on the king's row because of a capturing move then he must stop to be crowned even if another capture seems to be available. He may then use his new king on his next move.