A pitot tube is a device used to measure fluid flow velocity, commonly found in aircraft and various engineering applications. It consists of a tube with an open end facing the flow, which captures the fluid, and a side opening that measures static pressure. The difference between these two pressures helps determine the flow speed. In aviation, pitot tubes are crucial for providing accurate airspeed readings to pilots. They are typically mounted on the exterior of an aircraft and are connected to the airspeed indicator in the cockpit, ensuring safe and efficient flight operations.