a commercial enterprise that provides scheduled flights for passengers
"After booking my ticket, I checked in online to confirm my seat on the airline's morning flight to London."
A company that flies airplanes to transport people and goods.
"After comparing prices from several airlines, we finally booked our flight through Delta for next month's vacation."
In plain English: An airline is a company that operates airplanes to carry passengers and cargo between different cities or countries.
"We booked our airline tickets online last week."
Usage: An airline refers to the specific business or corporation that operates flights, not the physical aircraft itself. You should use this term when discussing ticket prices, baggage policies, or scheduled routes rather than describing an individual plane.
The word airline is a straightforward combination of the words air and line. It was first used to describe an organization that operates scheduled flights along specific routes.