Cloud computing (or cloud) has emerged as a breakthrough technology for sharing resources over the Internet. It is a newly emerging computing paradigm in which computing virtualized resources such as hardware, software, development, CPU, memory, network bandwidth, and data storage are provisioned as on demand services and released with minimal effort.Cloud computing refers to a setup of computing resources that can be shared anywhere, irrespective of the location of the users. It is the pay-as-you-go service for IT resources over the Internet, including applications, data storage, and data processing. Rather than building, owning, and maintaining their own IT infrastructure, businesses can use cloud to access technology resources such as computing capacity, storage, and databases on a pay-as-you-go basis. There is no doubt about the impact that cloud computing is having on businesses in all sectors.This is a comprehensive introductory text on the issues, ideas, theories, and problems on cloud computing. It is a must-read book for anyone who wants to learn about cloud computing, which is undoubtedly one of the most important technologies that has emerged in the last decade.