Basically the title, but I was prompted to find some help because my friend explained to me about how this guy he knows has a box with an antenna on it that plugs into a 3-prong outlet, and an ethernet port that goes to his pc from the box, since he is way too far from the router at his place and doesnt want to run a wire all the way across.

So firstly, can anyone identify the hardware he was talking about and explain how it works? And secondly, would this hardware be a drastic improvement for gaming via my laptop. Im currently on shitty wifi and thought there would be no hope to get anything better until I moved, but this could be a possible solution if good enough to game on.