It's a model of memory proposed in 1968 by Richard Atkinson and Richard Shiffrin.
It asserts that human memory has three separate components.
- A sensory register, where sensory information enters memory.
- A short-term memory that receives and holds information from the sensory register and the long-term memory.
- A long-term memory, where information that has been rehearsed in the short-term memory is held indefinitely.