Airline miles are a type of loyalty reward offered by airlines to encourage frequent travel. When passengers fly with a specific airline or its partners, they earn miles based on the distance traveled or the fare paid. These miles can be accumulated over time and redeemed for various benefits, such as free flights, seat upgrades, or other travel-related perks. Many airlines have their own loyalty programs, allowing travelers to join and track their miles. Additionally, miles can often be earned through credit cards, hotel stays, and car rentals, making it easier for travelers to accumulate rewards for their journeys.