It's designed to let you watch stuff from your home TV on a computer, is all. So if your Tivo is set to record all your favorite shows but you're out of town, you could stream whatever is recorded at home to your laptop (in an internet cafe, or hotel, or friend's house)- anywhere you have a broadband internet connection. I think it can even send TV shows to cellphones now.

The device is physically connected to your Tivo or TV tuner and plugged into your network at home.