Logitech Makes about 4 different internet radios.  They refer to them as Network Music Players.  They range from $200 to $2000.  Here is a high level overview of the Logitech Internet Radio Line

Squeezebox -- This is an internet radio recevier only, you will need a radio with speakers to listen to it.  Not sure but this may have been one of Logitechs first Internet radios. It supports WiFi and Ethernet.  It sells for $299.99.  Read the Logitech Squeezebox Review.

Squeezebox Boom -- This is an internet radio receiver with builtin speakers and remote controll. Read the Logitech Squeezebox Internet Radio Review.

Squeezebox Duet -- This is a remote control that is the radio tuner.  A small receiver connects to your stereo to send them music to your speakers.  This can be purchased as the Squeezebox Controller ($299.99) or the Squeezbox Receiver ($149.99) or both together as the Squeezebox Duet ($399.99).  It seems that they sell the part seperately so that you could have one controller that can be used in several rooms or incase you were to loose/break one of the peices. Read the Squeezebox Duet Internet Radio Review.

Transporter Network Music Player -- This is an extremely highend internet radio receiver.  It is a component that would attach to your home stereo.  At $1999.99 there should be some quality parts.  This receiver gives you just about everything you could be looking for. Read the Logitech Transporter Internet Radio Review

Questions to get answered:

Why would you want to buy the squeezebox instead of the Squeezebox Boom?

Why is the Duet also sold seperately.

About Logitech

Logitech makes high quality speakers and computer accessories.  They are one of the best companies with an excellent reputation.  Pretty much anything you get from Logitech is going to be good.