The sport of shooting, whether it's competitive pistols or noncompetitive hunting, is a broadly defined and popular sport. One of the common tools among those who enjoy shooting is a clay pigeon. A clay pigeon, also called a skeet, is a small, round disk that is flung into the air and then shot down. Many shooters use clay pigeons to improve their aim, reaction time, and even to practice hitting smaller, moving targets. However, even though skeet might look like a heavy frisbee, they aren't meant to be thrown by a person. As such, clay pigeon throwers, machines that fling skeet into the air, are most often employed.
One variety of clay pigeon thrower is a manual thrower, or a manual trap. A small, boxy machine, a manual trap can be set up at a variety of angles for different heights. A throwing arm that is attached to a powerful spring is then pressed back and then locked in place. A skeet is then loaded onto the arm, and released by pulling a cord or a lever. This action drops the lock, and the spring extends, flinging the clay pigeon up. Manual traps often require two people to use properly. One person to shoot, and a second person to "pull." This is why when a shooter is ready he yells "pull" as the signal for the second person to release the skeet.
There are also automatic clay pigeon launchers, or automatic traps, that may require only a single person to use. An automatic trap has the same basic set-up as a manual trap, except that the shooter may have a foot pad that he can step on to release the skeet at a pre-determined angle. Though not usually a feature of manual traps, automatic ones may launch clay pigeons along the ground in a rolling motion to simulate smaller game, for those who are interested in perfecting their hunter's eye. Other than this feature, though, the mechanics are roughly the same. The only other major difference is the price tag, with automatic traps being more expensive than manual.