As FOR says - an HDMI cable connects from the TV HDMI socket to the graphics card HDMI socket.
Note that the cable has a normal HDMI connector on one end and a small one on the other. I didn't realise that and bought the wrong cable for £9.99 from a local shop. Then bought the correct one for [ I think from memory] 99p off the internet. I've run it for some months now with good results.