In recently, the study of cloud computing attracts more attention with the quick development of wireless communication technology. What is a cloud computing? How to define it? What components it has? What relationships they have? Every one has its own idea. That is, there is not a universal definition at present. The most related works discussed the technologies used in cloud computing and the application areas in which cloud computing can be used. However, to our knowledge, there are few works which presented the relationships among them. Firstly, from the relevant database point of view, this paper drew a definition of view cloud and analyzed the relationships among the entities combined with the classical Entity-Relationship model. Secondly, from a new angle of view, this paper discussed the correlated theory of cloud computing with the concept database model, which has an active significance to understand the connotation of cloud computing and to better use it.
