Difference between the Xbox 360 Pro and the Xbox 360 Arcade?

Hello,
What is the difference between the xbox 360 Pro and the xbox 360 Arcade besides the price? I am going to buy one but i don't understand why one is cheaper than the other. And if you have any recommendations on which one to buy please comment.
Thanks for any help.

the arcade doesnt come with a hard drive, and as such cant be used for things like, live play and the downloading of extra content.

The Arcade also comes with a wired controller (at least that was the case the last time I checked) whereas the Pro has a wireless one, a mic-earphone headset & even a some cables to hook it up to the TV.

As a first time buyer you are better off going with the Pro or Elite (Pro was discontinued but some still have them in stock @ $250.). You'll get more out of it imo, as already described above. Here is a list http://en.wikipedia.org/wiki/Xbox_360#Comparison_of_features to compare but prices may be out of date depending on where you live.

well the arcade console has a with with disc try cover and a built in 256mb memory or card the pro console has a silver disc tray cover and cames with a hdd and they both hav wireless control's and the pro hasnt been discontinued the core console has

Both have been discontinued,

http://en.wikipedia.org/wiki/Xbox_360#Discontinued_models
http://www.xbox.com/en-us/hardware/compare101.htm

i wouldnt get eaither because xbox suck compared to ps3 here is a link for systems specs comparison http://www.ps3focus.com/archives/40 and unlike xbox u can play online for free instead of paying so basicaly ps3 is all around better then xbox.