Model of Working Memory
Working memory represents the active processing occurring in short-term memory. Overseeing the big picture is the central executive, which directs attention and integrates processing among three subsystems: the phonological loop, the visuospatial sketchpad, and the episodic buffer. To see how this model works, imagine you have stopped by the supermarket to pick up groceries. You rehearse the shopping list with your phonological loop, produce a mental layout of the store with your visuospatial sketchpad, and use the episodic buffer to access long-term memories and determine whether you need any additional items. Tying together all these activities is the central executive.

Source: Baddeley (2002)