5V Relay Module has 5V(+), GND(-), and S(signal data) and Single Pole Double Throw (NO, NC, and Common Connection). The Ratings for the relay should be marked on the relay itself.
To Use the Relay with Raspberry Pi connect the relay to a 5V pin, Ground, GPIO pin and also write a script to send a High to S to energize the relay or Low to Return to its denergized state.