A hockey stick is used as a lever. When you hold a hockey stick, the hand with which you hold the stick at the top end serves as the fulcrum. The other hand with which you catch the stick in the middle is at the end of the force arm. The other end of the hockey stick is used to strike the puck and this is where the end of the load arm lies. This is an example of a Class 3 lever.
This type of a lever makes it possible to apply a small force on the puck over a large distance by moving the hand in the middle by only a small distance though the magnitude of the force that has to be applied by the hand is several times higher.
Using the hockey stick in this way increases the speed by which the puck can be pushed. Pushing the puck at a higher speed is very important in hockey and provides a large advantage.