Southwest Airlines is the largest domestic carrier in the US based on passengers carried. It was founded in 1971 with a mission of providing low-cost, high-frequency, point-to-point flights. Southwest pioneered many customer-friendly policies like online booking and ticketless travel. It focuses on strong customer service and loyalty through low fares and programs like Rapid Rewards. Southwest uses a point-to-point routing on a single aircraft type to keep costs low and efficiency high.