Since the indoor game is played on a field that's roughly half the size of the outdoor field, it requires a stick that facilitates a faster level of play. Therefore, indoor field hockey sticks were designed to be much lighter and more flexible, allowing you to keep up with the quick pace.
Indoor field hockey sticks feature a thinner shaft and toe for a more lightweight stick that's easier to maneuver, allowing players to move, dodge, and shoot more quickly. They still have the same basic shape as outdoor sticks, flat on one side and curved on the other, but they do not require as much power as outdoor sticks. The thicker design and increased weight of an outdoor stick are crucial when driving the ball a farther distance and across the long grass. However, the playing surface is usually flatter indoors and the field much smaller, so the ball moves farther and faster by using much less force.
Depending on the league you are in, outdoor sticks can be used for the indoor game as well. However, the heavier the stick, the more difficult it will be to execute precision skills while maintaining the increased speed of the game.