The basic difference is ONE is corporate offering while other is community offering. If we consider all aspect then this would be very exciting to know that Hudson is the conventional name for Jenkins. Jenkins is the latest offering by the core engineers of Hudson. To know why you have to know the historical backdrop of the project. It was initially open source and bolstered by SUN System. Like quite a bit of what Sun did, it was GENUINELY open, yet there was a touch of amiable disregard. The source, trackers, site, and so forth were facilitated by Sun on their closed java.net environment. 

At that point Oracle purchased Sun. For different reasons Oracle has not been modest about utilizing what it sees as its assets. Those incorporate some power over the strategic platform of Hudson, and especially command over the product name. NUMEROUS clients and developers weren't happy with that and chosen to LEAVE. So it comes down to what Hudson versus Jenkins offers. Both Oracle's Hudson and Jenkins have the code. Hudson has Oracle and  Sonatype corporate help and the brand. Jenkins has the vast majority of the core engineers, the network, and (up until this point) considerably more genuine work.