[SOLVED] Why do some motherboards have PCIe and molex slots right on the motherboard?

[joeacejr15]

This picture will explain it perfectly. Its essentially asking why motherboards have PCIe cable slots and molex slots right on the motherboard. Dont these normally go on actual devices like video cards and hard drives?

 

[USAFRet]

no pic...

 

[NightHawkRMX]

Its for extra power to supply the pcie slots if you are running multiple gpus