The term "737" commonly refers to the Boeing 737, a popular narrow-body commercial aircraft designed for short to medium-haul flights. First introduced in 1968, it has become one of the best-selling jetliners in aviation history, with various models and configurations to accommodate different passenger capacities and ranges. The Boeing 737 is known for its efficiency and reliability, making it a preferred choice for many airlines worldwide. It features advanced technology, including modern engines and avionics, which contribute to fuel savings and reduced emissions, aligning with the industry's push for more sustainable air travel.