Almost all integrated circuits (ICs) have at least two pins which connect to the power rails of the circuit they are installed in. These are known as the IC's power supply pins. However, the labeling of the pins varies by IC family and manufacturer.
vSS: vSwitches are configured on each ESXi/ESX host. vDS: The configuration of vDS is centralized to vCenter Server. The ESXi/ESX 4.x and ESXi 5.x hosts that belong to a dvSwitch do not need further configuration to be compliant. These features are