Same chips, same video boards, same memory, same hard drives. Different BIOS and different OS, otherwise, mostly same stuff. Their Motherboards are Apple exclusive.

Interestingly we are having quality issues with one of the companies that Apple uses for printed circuit production. And we all know the stories of Foxconn... which is also used by many other hardware manufacturers. (contract assembly house)

Apple may have better QA, as that is done in house.

Apple certainly has higher prices.