The 2011 Pin system uses a Haswell 2011 pin Enthusiast processor. We commonly refer to this as a 2011 pin processor - which is actually referring to the number of pins found on the processor, not the year in which it was released.
The 2011 Pin processors come with either 6 cores or 8 cores, where as the normal Haswells have only 4 cores. The 2011 pin systems have a couple of other advantages: The motherboard can use more RAM so it is easy to install 64GB RAM which the 64 bit applications will use. The motherboard is more expandable in terms of the number of extra PCIe cards you can install. In a standard Haswell system you could have a graphic card, Blackmagic card, and maybe one other 1x PCIe card happily working. In the 2011 PIN there is room for these plus a RAID card, and possible extra FireWire sockets, as well as other interface card. This is particularly important for Resolve since you may want to have two powerful graphic cards in the system which you can only do properly on the 2011 Pin Haswell-E or Xeon systems and not on the normal Haswell