Difference between VM Network and VMkernel Network(Always confusing)

The main difference between VM Network and VM Kernel Network is their purpose.

VM port Groups are used only to connect Virtual machines to Virtual Switches.Primarily these can be layer 2 Switches which only need a tagging such as vLAN tagging to make sure that the Virtual machines communicate in between themselves,communicate in between the hosts,communicate to the internet etc. With VM Port groups,you can have policies such as Security,Traffic Shaping,NIC Teaming etc.

VMkernel ports are used to connect the VMkernel to services that it controls. There can be many vmkernel ports however there is only one vmkernel. Hence the vmkernel ports can be differentiated based on the service it connects the vmkernel to. The services might be vmotion,SCSI binding,Management of the ESXi or Fault tolerant.