The Boeing 737 is a popular short- to medium-range twinjet narrow-body airliner, first introduced in 1968. Known for its reliability, efficiency, and versatility, it is the best-selling commercial jet in history. The 737 family includes several variants, accommodating 85 to 230 passengers, depending on the model. Its design features two underwing engines and a distinctive fuselage cross-section. The aircraft is favored by airlines worldwide for its operational flexibility, serving both domestic and international routes. Continuous upgrades, such as the 737 Next Generation and 737 MAX series, have kept the aircraft competitive in modern aviation markets.