Usually it is distinguished:
- Sensory memory - keeps the sensory information for a very short time (less than 1 second) - visual information stores iconic memory; auditory information store echoic memory
- Short-term memory - an ability to temporarily (15-30 seconds) hold the information for a period needed for processing - short-term memory capacity is likely to be the magic number 7±2 (G.A. Miller, 1956) - information is stored in chunks, they are logically consistent units of information
- Long-term memory - used for long-term storage of massive amounts of information, divided into:
- Explicit memory - stores facts and concepts (semantic memory) and events (episodic memory)
- Implicit memory - stores primarily automated motor or cognitive skills (procedural memory)
Quality of memory is closely correlated with intelligence, because when measuring intelligence, the memory is an important part of it.