WEB 2.0 (or Read-Write-Web, or…), being most of all a boom in technology development and a change in the users’ behavior, that’s far from the whole, Cloud Computing brings what was missing: users’ interface homogenization, interoperability, better access control and Identity management, business models, etc. All this things are part of other paradigms, concepts and technologies, but Cloud Computing tries to group everything in a concise and clear way.