Unlike memory, this type of storage holds data and programs even after electrical power to the computer system has been turned off.

Secondary memory.

Explanation:

Unlike main memory which loses its content when electrical power to the system is turned off, secondary memory is volatile and persistent in nature. i.e it retains its content whether or not power is supplied to the computer that is holding it. As a matter of fact, they (secondary memory) are meant to store data permanently. Examples of such memory are the hard drives, floppy disks, flash drives, CDs and CDROMs.

Also, unlike the primary or main memory that can be accessed directly by the processor of the computer housing it, secondary memory are not accessed directly.

the difference is right there dont you see it

make sure each item is its own paragraph.