The Contents of This Book Represent A Series Of Lectures Given In The Working Member Of Project On Cloud Computing and Technical Research Level Class On Cloud Computing. We have great pleasure in presenting the First edition of this book. ¿CLOUD COMPUTING AND CLOUDY COMPUTER¿ is a core subject for Ph.D. ,M.Tech, ME, B-Tech, BE, MSc, MCA and Diploma Students. This book is primarily intended to serve as a textbook in according with syllabus of cloud computing and cloudy computer offered by various universities in India as well as abroad. Cloud computing is a movement started sometime during the middle of the first decade of the new millennium; the movement is motivated by the idea that information processing can be done more efficiently on large farms of computing and storage systems accessible via the Internet. The appeal of cloud computing is that it offers scalable and elastic computing and storage services; the resources used for these services can be metered and the users can be charged only for the resources they used. Cloud computing is cost effective because of the multiplexing of resources. Application data is stored closer to the site where it is used in a manner.