Can someone explain to me what the Airport Extreme Base Station is?

[the big kx]

Is it basically a router?

How does this go with it and what exactly does this do:
http://store.apple.com/ca/product/M...ess-AirTunes?fnode=MTY1NDEyMQ&mco=MTMzODA4MDc

 

[MacMini2009]

Yes, it is basically a router. Just connect your modem to it.

 

[flopticalcube]

How does this go with it and what exactly does this do:
http://store.apple.com/ca/product/M...ess-AirTunes?fnode=MTY1NDEyMQ&mco=MTMzODA4MDc

The Airport Express is a smaller version of the Extreme. It has only one ethernet port and the USB can only connect printers. It has the advantage of running Airtunes.