Low-cost airline, budget airline, discount airline or no-frills carrier

A low-cost carrier or low-cost airline is an airline that generally has lower fares and less comforts. These airlines may charge for extras like food, priority boarding, seat allocating, and baggage etc.

Low-cost carrier business model usually includes:

• only one passanger class
• limited variety of aircrafts to minimize training costs
• development of one of more hubs to maximise destination coverage
• flying to cheaper secondary airports
• unreserved seating
• direct sales of tickets (usually own website)
• passengers paying charges for extras, such as hold luggage, online check in and priority boarding
• not supplying meals in a flight, but offering snacks, sandwiches and drinks instead to purchase on board

This list of budget airline business model is a summary of the characterics defined at wikipedia. Usually Southwest Airlines (1971) is considered as the first low-cost airline.