How does HIV live?

CDC says that HIV does not survive long outside the human body and that they can only survive for days or weeks in labs under the right conditions.  So what are the requirements for HIV to survive outside the human body?  I looked on the web and all I can find is how it takes over the T cells, which I already know.  I think we talked about this back in college, but I just can't remember.  Does anyone know?  My assumption is that HIV can only survive when there are T-cells and T-cells just don't survive anywhere else other than the human body.  Thus, HIV can't survive outside the human body or without T-cells.  Is that correct?  And, can someone give me a clear definition of activity and inactivity of HIV?

[Teak]

HIV is not alive. It is either active or inactive. HIV is not transmitted outside it's host.