Air cannons are devices that use compressed air to launch projectiles or create bursts of air. They are commonly used in various applications, including sports, entertainment, and industrial processes. The mechanism typically involves a chamber where air is compressed, and when released, it propels an object at high speed. In sports, air cannons can be used to launch t-shirts or other promotional items into crowds during events. In industrial settings, they may help in clearing debris or moving materials. Overall, air cannons are versatile tools that utilize the power of compressed air for different purposes.