How do psychologists describe the human memory system (i. e., understand the 3-stage processing model of memory and the concept of working memory)?

Memory models are usually used by psychologist to describe the human memory system. The Atkinson-Schiffrin model is composed of three processing stages, namely: short-term memory, long-term memory, and the sensory memory.

The Atkinson-Schiffrin model has been recently updated to only have two important concepts: the working memory and the automatic processing. The active processing that occurs in the second memory stage is stressed in the working memory concept.