Revision with unchanged content. The availability of information has always played a key role in the value creation process but the technological improvement in how to deal with data, has lead to a situation of information excess: today the information is not anymore a scarce resource and, then, its economic value decreased. As consequence, in the current competitive environment, it is the knowledge, that is the ability to deal with data and information in order to get the right decisions, which enables companies to obtain and maintain a sustainable competitive advantage. Knowledge, from the past role of resource, becomes the company's focus, generating a new critical asset that is called 'the Intangible'. The present work shows some frameworks used to measure intellectual capital. Moreover, as the essence of Intellectual Capital is to be pure knowledge, the work is mainly focused on the concept of knowledge as information that generates further information through the discretional effort spontaneously offered by an employee because of the stimuli received by the organization.