motherboard companies do not produce all the components that you find on it. They actually assemble all the parts and present it in market. For that they acquire different parts from different places. the PCB (printed circuit board) itself comes from a different company. For ex:
say GIGABYTE mobo: The socket, the ram slots, the northbridge, south bridge, PCI, PCIE all these are assemled in the factories of GIGABYTE. According to the processor mobo socket will vary. For INTEL, socket will be of INTEL LINE for AMD, socket will be of AMD LINE. Now each type processor supports upto a level of socket on which it sits. So with evolution of PROCESSORS socket also changes. in each mother board the total components are divided into three parts. refer this According to the pic the main three parts are the socket, northbridge and southbridge controll total mobo components. The chipset with "g" means integrated graphics and without means separate GPU required for display in monitor.
FACTORY TOUR
nan-ping
Hope this will throw some light.