Chrome case connects to both the HDMI and the USB port on the TV... It receives "Casts" from either your laptop/smart phone/ and so on or from the net.
However streaming video from the net is very bandwith intensive, if you are on an unlmited plan. No problem,, Throttled if you use too much plan, count on getting throttled... Pay for overage. LOOK OUT... Park Wi-Fi, please leave some for others and do not use Chromecast for streaming FROM THE INTERNET....
One of my TV's lets me plug in a flash drive with an MPG4 on it and away it goes.