What is the difference between an LGA 1151-2 socket and a LGA 1151 socket

Solution
LGA 1151 (100/200 series) is used for 7th and previous generations Intel CPUs.

LGA 1151-2 (300 series) is used for 8th and 9th generation Intel CPUs.
Heh, 'working' is subjective. They get past bios and can do simple stuff in windows, but have yet to get full functionality and stability as the ram/mc issues are throwing a fit.

Yeah, lga1152 would be physically incompatible. All in the name of saving a buck on some re-tool and die.