Wikipedia says this about it: http://en.wikipedia.org/wiki/Active_directory
How is Active Directory different from Administrative Install for SW deployment? I get that it is only available on a Server OS, so I can't actually set it up on my home or business license OSs.
There is a common misconception that Active Directory provides software distribution. Software distribution is run by a separate service that uses additional proprietary schema attributes that work in conjunction with the LDAP protocol. Active Directory does not automate software distribution, but provides a mechanism by which other services can provide software distribution.
Again, I need an explanation in really small words. I just don't get what it does or what you would use it for.