Criteria

Primary Memory

Secondary Memory

Connection of memory to the CPU?

Directly

Indirectly

Store data temporarily or permanently?

Temporarily (i.e. volatile)

Permanently (i.e. non-volatile)

What data and information it stores?

It holds data and instructions on which the CPU is currently working.

It holds data and information which are not currently required by the CPU

Access time (time required to load data from the memory into register)

Less

Much

Speed

Higher

Lower

Cost per bit

High

Low

Storage capacity

Limited

High

Examples

RAM

Hard disk, CD, DVD etc