Fan cable set up help

I just bought new parts for a PC build and I got my hands on the radiator for it. However I’m looking at the fans and they have these different plugs. I’ve never seen these kinds of plugs and of course the box didn’t come with any instructions for them. Only talking about how to screw them on. So I need help understanding what goes where. I has what looks like the usual power cables for them, but then they have these 3 pronged socket (with a space between one) with a matching pin one on the other end of the cable.