In search results, Skyscanner displays marketing and operating carriers.
When a codeshare agreement exists between two or more cooperating airlines, they share the right to market, or sell, the same flight. These sellers are called marketing carriers.
Each of these marketing carriers is allowed to publish and market the same flight under their own unique two letter IATA code and flight number (ex. LL 0456).
While multiple airlines can market the same flight, only one is able to physically operate the flight. The airline who conducts the flight the day of travel (provides the plane, crew, etc) is the operating carrier.
A marketing carrier can also be the operating carrier if they market AND operate the flight themselves. If this is the case, Skyscanner will not list the operating carrier in the search results. If the operating carrier is different from the marketing carrier a message will appear below the itinerary leg stating "operated by XX airline"
All of the below are the same flight operated by LL airline but marketed by airline MM, NN, OO, and PP.
LL 0456 = MM 1234 = NN 567 = OO 345 = PP 9867
Where XX= Airline IATA code and #### = Flight Number