Southwest Airlines is a major U.S. airline, the world’s largest low-cost carrier, headquartered in Dallas, Texas. The airline was established in 1967 and adopted its current name (Southwest Airlines) in 1971. As of 2014, it carries the most domestic passengers of any U.S. airline. As of January 2016, Southwest Airlines has scheduled service to almost 100 destinations in 40 states, Puerto Rico, and abroad. As of January 2016, Southwest is the largest operator of the Boeing 737 worldwide, with over 700 in service, each averaging six flights per day.
Source: Wikipedia