Cloud Computing=Cluster Computing +Grid Computing

 In above Diagram we can see that clouds were contains the data of organizations  and it contains more than one server so these are the CLUSTERS and all Clusters were connected to each other and all Clusters are in one NETWORK so it is GRID and and overall it is a “CLOUD COMPUTING”.

                                                 In Cloud Computing all set of servers that is CLUSTER'S are connected to each other so that it works as one SYSTEM.we can access our data anytime anywhere by using INTERNET.

Cloud computing is an extension of the object-oriented programming concept of abstraction. Abstraction, as explained earlier, removes the complex working details from visibility. All that is visible is an interface, which receives inputs and provides outputs. How these outputs are computed is completely hidden.

 A cloud is similar; it applies the concept of abstraction in a physical computing environment, by hiding the true processes from a user. In a cloud computing environment, data can exist on multiple servers, details of network connections are hidden and the user is none the wiser. In fact, cloud computing is so named because a cloud is often used to depict inexact knowledge of inner workings.