Differentiate the function of SDRAM and HDD?

SDRAM(Synchronous_dynamic_random_access_memory) i.e. your primary Memory, before execution of any program the piece of that program must be bring into the RAM(Primary Memory).

HDD (Hard Disk Drive) is Secondary Memory where all static program resides. Your whole file system of operating system, your data ie your songs, pictures, movies resides in your HDD even if there is no power. It it another thing that you can't excess during no power.means it is not volatile in nature.

Where as whole content of SDRAM vanished when power goes off, ie. SDRAM is volatile in nature .

:)

search in wikipedia for more details:

RAM

http://en.wikipedia.org/wiki/Synchronous_dynamic_r...

http://images.google.co.in/images?q=SDRAM&oe=utf-8...

HDD

http://en.wikipedia.org/wiki/Hard_disk

:)