Over the years, the commercial aviation industry has changed significantly. In the early 20th century, commercial air travel was utilized only by the wealthy as a niche mode of travel. However, as the decades passed, the commercial aviation market has evolved into a global network that connects billions of passengers and thousands of tons of cargo. As jet engines and long-range aircraft were introduced, airlines became capable of linking continents and revolutionizing global transportation. Along with the deregulation of the airline industry, carriers could compete freely on routes and pricing.