What is an airline alliance and what are Star Alliance, oneworld, and SkyTeam?

An airline alliance is a partnership between multiple airlines that allows passengers to earn and redeem loyalty miles across all member airlines, share lounges, and connect on partner flights with seamless baggage transfer.

The three major global alliances:

Star Alliance (26 members) — includes: Lufthansa, United Airlines, Air Canada, Singapore Airlines, Thai Airways, ANA, Turkish Airlines, EgyptAir, Ethiopian Airlines, TAP Air Portugal, LOT Polish Airlines, and others.

oneworld (14 members) — includes: American Airlines, British Airways, Cathay Pacific, Japan Airlines, Qantas, Iberia, Finnair, Malaysia Airlines, Royal Jordanian, Royal Air Maroc, SriLankan Airlines, and Qatar Airways.

SkyTeam (19 members) — includes: Delta Air Lines, Air France, KLM, Korean Air, Vietnam Airlines, Garuda Indonesia, China Eastern, ITA Airways, Kenya Airways, and others.

Practical benefit: If you fly American Airlines (oneworld) to London and then British Airways (also oneworld) to Rome, you earn miles in the same program (AAdvantage) for the entire journey.