Can someone explain these to me as I am still a bit shady when it comes to reading about these.

I have just read that George Groves vs James Degale purse bid was won by Hayemaker for £400k. What does this actually mean? And how did they get to this figure? Am i right in thinking if two promotors can't agree terms, they go to a (sort of) arbitrator and people bid for the rights to host the event? Is the £400k split between the fighters?

Just need a quick explanation.