Net Meeting

I discovered that I have Net Meeting on XP. I have installed it, but do not know how to use it to video conference. Any suggestions? What is the relationship between Net Meeting and MSN Messeger? I receive a Message that MSN Messenger has supplanted the Directory for contacts. Do I need to download and install MSN Messenger? How does Windows Messenger fit in? XP comes with Windows Messenger; is Windows Messenger alone with Net Meeting all that is needed to contact someone (NET Passport) or are all three: Net Meeting, MSN Messenger and Windows Meesenger neccessary? Thanks, Mike.