What is code sharing in the airline industry?

Question

What is code sharing in the airline industry?

Answer 1

Airlines frequently use code-share agreements allowing them to market seats on flights operated by partner airlines or you may say, code-share is an arrangement whereby an airline sells seats, under its own name, on another carrier's flight.

Answer 2

It's where two flights (i.e. BA1234 and NZ457) are actually the same aircraft...

Answer 3

Just to elaborate on what Mark answered;

I recently flew to Korea on Delta flight 91, which was also known as Korean Air flight 7825.  The flight was operated by Delta.  Later in the day there was a flight that was Korean Air flight 7898 (not the actual number) and Delta flight 71, which was operated with a Korean Air airplane.  Normally, if a flight is going to a foreign country it will have a code-share number with an airline from (or that operates predominantly) from that country.  Flying to the Netherlands, you will probably have a codeshare flight with Northwest Airlines (for example) and KLM, Germany: Delta/Lufthansa.

Hope that helps.