The knowledge based society developed the new technologies of information and communication in order to use better all the data at different levels and to manage them efficiently. Computers have the capacity to store information, to select it, or to provide it. Human mind, memory and other capacities, are replaced by the upgraded capacities of the computers. Computers are able to store just semantic information, but they do it better than any human epistemic subject. Computers incorporates tacit knowledge and use it also as information or rules to manage the data. Therefore, in KBS the human transition from information to knowledge is accompanied by a reverse computational transition from knowledge to information.