Southwest Airlines is a major domestic airline that provides primarily short-haul, high frequency, point-to-point, low-fare services in the United States. The company commenced customer service in 1971. It now operates almost 400 Boeing 737 aircraft in 58 cities and offers a low and simple fare structure. The company’s frequent daily flight routes include Dallas to Houston, Phoenix to Las Vegas and Los Angeles International to Oakland. Southwest’s long-haul non-stop services include Baltimore to Los Angeles, Phoenix to Tampa Bay, Seattle to Nashville, and Houston to Oakland.