We have a desktop in a room where the is no wired connection that has bad reception from the wireless AP. Someone (I don't remember who of course) told me there are high gain antennas that will make it possible to get a better reception (and throughput). I believe he said they are adaptors with "high gain" antennas.

He also told me he uses it in hotels when he has a bad WLAN reception. When he connects that card the reception and speed is a lot better all of a sudden.

But can someone explain me in understandable language what that is and what the thing with high gain, dB, dBi and mW is all about please? What type of card do we need? On like this or this?