so what are the differences? had to go on communicator at the office but i dont really know why

 

Communicator is for internal use mainly. It allows you to have presence awareness in MS applications like Office, SharePoint, Exchange, etc. I believe it can be connected to MSN Messenger but not certain. We just purchased AD, Exchange, SharePoint, Commnicator, etc. las year and I am starting the project now for AD and Exchange.