Unbuffered memory is volatile memory which is the module of choice for personal computers and workstations while it is not suitable for servers. Unbuffered memory is accessed directly by the memory controller where as Buffered Memory "caches" or stores and forwards the contents prior to the controller's access therefore buffered memory is more suited for server needs.

In the past, registered memory was called buffered memory and unregistered memory was called unbuffered memory. Registered memory got renamed in common use, but unbuffered memory did not.