Ferrets are in fact domesticated animals and probably originate from the European Polecat. Ferrets belong to the weasel family (latin: Mustelidae) which also contains animals such mink, pine martens and badgers. They make good pets given the right conditions but just like all domesticated animals need to be properly looked after.
The RSPCA has more info about Ferrets on their website. Ferret groups are also active on Facebook.