The corner kick was introduced under the Sheffield rules in 1867. It is a way of restarting play in soccer after the ball has left the field of play over the goal line. A corner kick is awarded to the attacking team after the defending team has touched the ball last.
The assistant referee is usually the official who calls a corner kick, and they will do so by raising their flag into the air and pointing it towards the corner arc.
After the corner kick is called, the ball is set down within the corner arc closest to where the ball went out of play. The corner arc is the semi circle located at one of the corners near the goal and touchline and has a radius of one yard.
The defending players must back up at least 10 yards (9,15m) from the ball until the corner kick has been taken.
Although opionion is divided on the subject it is widely accepted that the attacking team can score directly from a corner kick. This is referred to as an Olympic Goal.