Airline loyalty programs are rewards systems offered by airlines to encourage repeat business from travelers. Members earn points or miles for flights taken, which can be redeemed for free flights, upgrades, or other benefits. These programs often have different tiers, with higher levels providing additional perks like priority boarding and access to exclusive lounges. To join a loyalty program, travelers typically sign up for free and start accumulating points with each flight. Many airlines also partner with hotels, car rental companies, and credit card providers, allowing members to earn points through various travel-related purchases, enhancing their overall travel experience.