Okay?! As stated you need to explain in detail your question(s) and specific software.
The term (noun) 'RAM' or memory or RAM Kit or RAM stick (individual 'piece' of RAM) - can all be used in the context of RAM.
There's folks that use USB Flash drives for ReadyBoost for a disk cache if they have <1GB of RAM, but it's not a substitute for 'RAM.'
There are applications that can 'trick' 32-bit OCes to use the full 4GB (or more GB's) of Physical RAM. Example - http://www.geoffchappell.com/notes/windows/license/memory.htm
Other than that I'm guessing here...