According to the stage-model, there are three memory systems through which information is processed. These are – sensory memory, the short-term memory and the long term memory.

(i) Sensory memory: The incoming information first enters the sensory memory. Sensory memory has a large capacity. However, it is of very short duration i.e., less than a second. It is a memory system that registers information from each of the senses with reasonable accuracy. Often this system is referred to as sensory memories or sensory registers because informations from all the senses are registered here as exact replica of the stimulus.

(ii) Short-Term Memory: Information that is attended to enters the second memory store called the short-term memory (STM), which holds small amount of information for a brief period of time (usually for 30 seconds or less). As Kinson and Shiffrin propose that information in STM is primarily encoded acoustically i.e., in terms of sound and unless rehearsed continuously, it may get lost from the STM in less than 30 seconds. The STM is fragile but not as fragile as sensory registers where information decays automatically in less than a second.

(iii) Long term Memory: Materials that survive the capacity and duration limitations of the STM finally enter the long-term memory (LTM) which has a vast capacity. It is a permanent storehouse of all informations. It has been shown that once any information enters the long-term memory store it is never forgotten because it gets encoded semantically, i.e., in terms of the meaning that any information carries.