The object of the sport of wrestling is to put your opponent on his back -- to pin your opponent.
A pin (or fall) is when you put your opponent on his/her back with any part of both shoulders or both shoulder blades of your opponent in contact with the mat for two seconds. When you pin your opponent, the match is over and you are the winner.
If nobody gets pinned, the winner is the wrestler who has scored the most points during the match..