Here is the Microsoft version of XP Pro and Home comparison:
http://www.microsoft.com/windowsXP/h.../choosing2.asp
Basically, XP home can't join the domain server for authentication and can't join Novel server (not mentioned on MS site), Microsoft don't allow IPX protocol to be installed on XP home.
Here is how I put it: XP home is a washed down version of XP Pro.
cheers