Aviation is a term used to describe the science and practice of flight. Synonyms for aviation include aeronautics, air transportation, flying, and air travel. Aeronautics describes the study and technology of flight within the Earth's atmosphere, including the design and manufacture of aircraft. Air transportation is the movement of passengers and cargo by air, with a focus on commercial airlines. Flying refers to the act of piloting an aircraft, while air travel encompasses all aspects of traveling by air, including check-in, boarding, and in-flight service. In addition, terms such as aerial navigation, aerodynamics, and aviation industry are also associated with the broader field of aviation.