ram and rom is a 
semiconductor memory of 
a computer system.ram is 
based on 2 types of 
semiconductor 1.static 
ram 2.dynamic ram.dram 
requires periodic 
refreshing to maintain 
data but sram not 
required.Rom is a 
non-volatile memory.Rom 
devices are typically used 
to store low level 
harware instructions that 
do not change,such as 
programming for post 
test,initialization routines 
and boot loader routines 
in the system's BIOS 
device.
flopy is secondary memory 
for computer system.

ram means read access memory i.e,it can be used reading and
writing
rom means only it can be read only memory
flopy disk means it restore only data
hard disk means it can restore data vedio files