RegisterFactory vs. RegisterFactoryLocation

Hello!
What exactly is the difference between RegisterFactory and 
RegisterFactoryLocation? What does the latter do that the former doesn't?

Can I change existing code to use RegisterFactory instead of 
RegisterFactoryLocation and will it still work?

Thanks,
Christian
-- 
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
                                                  -- Benjamin Franklin