Turbulence is the chaotic and irregular movement of air that can cause an airplane to shake or bump during a flight. It happens when the plane flies through different air currents, which can be caused by weather conditions, mountains, or even other aircraft. Pilots are trained to handle turbulence, and modern planes are built to withstand it, making flying safe even when the ride gets bumpy. There are different types of turbulence, such as clear air turbulence, which occurs at high altitudes without any visible clouds, and thermal turbulence, caused by rising warm air. While it can be uncomfortable, turbulence is a normal part of flying and usually lasts only a short time.