The book "Computer Science and Network Technology" gives an in-depth discussion of the key systems in the development of distributed software and service-oriented systems through the Internet, and gives readers some critical thinking and technical skills about development and performance assessment of such systems. This book defines the Internet and World Wide Web (WWW) as the core technologies of our society, which have changed the design and configuration of software systems. It also touches on emerging network technologies, such as software as a service (SaaS) and cloud-based paradigms, which have enabled new ways to provide and utilize computing and IT resources across the Internet.