Commercial flights are scheduled air travel services that transport passengers and cargo between various destinations. These flights are operated by airlines, which provide a range of services, including ticket sales, in-flight meals, and entertainment. Commercial flights can vary in size, from small regional jets to large international aircraft, accommodating different numbers of passengers. Airlines typically offer different classes of service, such as economy, business, and first class, each with varying levels of comfort and amenities. Flights are usually booked in advance, and passengers must adhere to security regulations at airports before boarding.