A water pipe is a pipe that uses water to cool and filter the smoke. The bowl of a bong/water pipe is similar to that of a hand pipe, but it connects to a longer tube that’s filled with water. When you inhale, the smoke travels from the bowl to the main tube of the bong. Water-soluble components of the smoke – such as ash, tar and resin – remain in the water. The resulting smoke is cooler and smoother, allowing you to inhale more deeply without irritation.