This is a 5V 8-Channel Relay interface board that can be used with an Arduino or Raspberry Pi. The Raspberry Pi can switch the relays directly because of the optocouplers that are used to toggle the relays.
5V 8-Channel Relay interface board
Equipped with high-current relay, AC250V 10A ; DC30V 10A
Standard interface that can be controlled directly by microcontroller
The Arduino 4 Relays Shield is a solution for driving high power loads that cannot be controlled by Arduino's digital IOs, due to the current and voltage limits of the controller.
The Raspberry Pi Relay Board gives your Pi the ability to control high voltage/high current devices, easily makes normal home appliances become intelligent devices.