Yes. This called CODE SHARE. This means that one airline , in this example British Airways sell some of their seats to Iberia. Airlines do this to offer their customers, in this case Iberia the route without the expense of actually having a plane on that route. It also means that British Airways are more likely to fill the plane by sharing some of the seats with Iberia, than just relying on selling the seats themselves.
Just a note about using Skyscanner. The more changes there are, the chaeper the flight will be. You can select direct or just one change, which when flying long haul is far less stressful then multiple plane changes
