Question : domain vs workgroup

I am not really understanding what a domain is versus a workgroup. All I know is that a workgroup is for xp, 98 and now 2003

I have 1 server that is a domain controller and has an active directory with users listed with passwords.  I am not sure the point of it though. Each xp pc has 2 accounts currently on it. 1 for admin and the other the user name.

Answer : domain vs workgroup

A domain allows you to setup user accounts on ONE system and use them on ANY system that is a MEMBER of the domain (XP/2000/NT/20003 that are configured to work in a domain and not a workgroup and 9x machines configured to log on to the domain).  Further, with a Domain, you can assign security to users, computers, deploy software to all computers without sitting in front of them, and basically have MUCH greater management abilities