The development of Cloud computing have led to a renewed interest in the all fields of computing. The book describes the development of Grid computing and Cloud computing. Cloud computing is currently widely used by most medium to large size companies. In addition to storing large amounts of data, cloud computing also offers computing facilities to users. This book describes the basic features of cloud computing and gives examples of commonly used cloud computing architectures. The decision to whether or not to introduce cloud computing to a business is not easy. After reviewing the basic decision theory the book explains in detail how a decision can be made before cloud computing can be accepted or rejected by a firm. The book should be useful to any firm of any size interested in investing in cloud computing, but who may want to learn more about this technology before making the decision.