Knowledge Management Systems (KMS) studies, with roots from the information theory, knowledge and knowledge management (KM) has increased during the past years and moved to a broader spread of occupations. Therefore, a need of a literature review on the field of KMS arose and is fulfilled in this article. From selected ample scientific articles in the field some major similarities and controversies as well as research gaps were discovered.  Conclusions from the review result in that even if there are some differences in the field regarding knowledge and KM most authors agree on the bases of KMS. Another conclusion result in a connection to the information theory that mainly concern about information exchange and the relevant process, which was first developed by the founder Claude E. Shannon from the thematic school.