A "Single-Aisle" aircraft is a type of commercial airplane designed with one aisle running down the length of the cabin. This configuration typically allows for seating on either side, accommodating a moderate number of passengers, usually between 100 to 240. Examples of single-aisle aircraft include the Boeing 737 and the Airbus A320. Single-aisle planes are commonly used for short to medium-haul flights, making them popular among airlines for regional travel. Their design enables efficient boarding and deplaning, which helps reduce turnaround times at airports. This efficiency is crucial for airlines operating in competitive markets.