Am newbie to Arduino I have 2 Relay Module opto isolated and Arduino UNO i have written simple program to control relay i have connected vcc to 5v from arduino and GND TO GND from arduino also JD-VCC and vcc are short circuits. My problem is Led from relay works fine but my relay coil is not energized. Thank you
Need a wiring diagram - the Arduino probably can’t supply enough current to power a relay direct
You need a 5 V power supply to run the relay board.
If you are running the Arduino - ?UNO - from the "barrel jack" or "Vin", the on-board regulator is capable of powering the microcontroller itself, but not other devices such as relays connected to the 5 V pin.
If you have a proper 5 V power supply, connect it to the 5 V pin and ground as well as the relay board. Or, a "phone charger" which is a 5 V regulated power supply can power it through the USB jack (up to 500 mA).
Thank you for help but i have used external 5v power supply from mobile charger with 800mA o/p and i have supplied separate power for Arduino but this only blinks the Led and i supplied 5vdc to relay coil on back of board and the relay ticks and works fine. Then i have supplied 12vdc as separate input for relay and both relays closed and they can't be controlled when i unplug the power the relay return to its state. I need more help thanks
OK, clearly something is wrong here but I will want a diagram (and proper photo preferably) of all the connections to discuss this further.
When I wake up that is. 
okay i will send but i need time