This paper presents a review on the concept of Working from two main approaches. On the one hand the cognitive psychology, particularly in the learning and memory fields, while on the other hand it is presented the perspective from neuroscience data: clinical and experimental. It is referenced the prefrontal syndrome from a historical point of view, additionally some electrophysiological, functional imaging, and cortical ablations works are summarized. At the end of the document it is also introduced, a model of the cortical circuitry concerned with working memory processing; five circuits are considered: cortico-cortical as well as cortico-sub cortical loops are depicted.