What is 'system idle process'?

[Fisher]

Wow, just on the net, with a few programs running in the background (i.e, in taskbar) my CPU's only using 2-4% when I move the mouse... and yet, the processors at a toasty 47 degrees C hmm...

47 degrees C! wow what temp is it when it idles for a while?

 

[Kage]

Well its running 3D software, MSN, and this website, and its now at 8-24-48% CPU useage, and has shot to 55 degrees C... (It stays at about that)