Airline business models have changed significantly since the dawn of commercial aviation in the early 20th century. Initially, airlines were heavily subsidized by governments and operated as public utilities, offering scheduled services to a limited number of destinations. After World War II, airlines expanded their networks and introduced innovations such as jet engines, pressurized cabins, and in-flight entertainment. However, they also faced high costs, overcapacity, and regulation that restricted their pricing and route choices. In the late 1970s and early 1980s, the deregulation of the airline industry in the US and Europe opened up new opportunities for airlines to compete on price, service, and efficiency. This led to the emergence of new business models, such as low-cost carriers, regional carriers, and charter airlines, that challenged the dominance of the traditional full-service carriers. Since then, airline business models have continued to evolve in response to changing customer preferences, environmental concerns, technological advancements, and market dynamics.