-Non Volatile.Holds the programs and data event when computer is turned off .
Data from ROM can just be read only Ram
-Volatile,which means the program and data will be lost when the computer is turnes off .
Data from RAM can be read or retrieved and written or stored during processing. Secondary
Is an alternative storage.It is very useful to store programs and data for future use.Magnetic Medium
MAgnetic disk.>Floppy disk,hard disk
Magnetic tape.>Video cassette,audio storage Optical Medium
Cd,CD-Rom &DVD,CD-Rw, DVD-Rw and DVD-RAMFlash Memory
Memory card,Flash drive