PHYSICAL and SECONDARY MEMORY

Physical Memory
Also referred to as the physical storage or the real storage, physical memory is a term used to describe the total amount of memory installed in the computer. For example, if the computer has two 64MB memory modules installed, it has a total of 128MB of physical memory.

Secondary Memory
Secondary memory (or secondary storage) is the slowest and cheapest form of memory. It cannot be processed directly by the CPU. It must first be copied into primary storage (also known as RAM ).
Secondary memory devices include magnetic disks like hard drives and floppy disks ; optical disks such as CDs and CDROMs ; and magnetic tapes, which were the first forms of secondary memory.