This book addresses Cloud concepts, including advanced forward-looking concepts and how these concepts are realized or implemented in practical systems or frameworks. For example, when a Cloud user or tenant requests a service from a Cloud or Cloud service provider the step-by-step processes of what happens underneath or under-the-hood will be described employing a Cloud framework, such as opensource Openstack, thus bridging the concepts to practical realization of the concepts. The substantial focus of the book is on Cloud networking, the new generation networking that makes a network Cloud-ready, such as VM networking and next-gen DC technologies supporting multitenant Cloud DC. In addition, programmable or software-defined networking that makes on-demand networking possible are also discussed in detail (the on-demand aspect, where compute, storage and network resources are CRUD: Create / Read / Update / Delete almost immediately, is a major feature or requirement of a Cloud). Furthermore, the author discusses how Cloud concepts, features and programmable networking come together to build truly programmable Cloud that spans wide network domains (from tenant intranet or private Cloud to MAN/WAN to one or more public Clouds and their Cloud DCs).