Chapter 1 and Chapter 2 of this book are the basics of cloud computing, including the emergence, development and basic concepts of cloud computing; Chapter 3-8 are concerned with the technical aspects of cloud computing, including the key technologies for implementing cloud computing: virtualization, cloud security, distributed file systems, data processing and parallel programming technology and distributed storage systems; Chapter 9 mentions to the readers some of the popular applications of cloud computing at present; and Chapter 10 is comprehensive practices: it is mainly about practices in which experiments are conducted for readers to understand the construction of mainstream public cloud AWS, the more representative domestic private cloud vendors and the open source private cloud Openstack as well as practices integrated with docker technology.