This document discusses Docker Containers as a Service (CaaS). It begins by showing how Docker can be used to build a software layer on top of the internet hardware layer. It then discusses how Docker can be used with different cloud platforms and orchestration tools. It presents Docker CaaS as addressing the needs of both developers and IT operations by supporting the full application lifecycle across any infrastructure or operating system. Key characteristics of Docker CaaS include open APIs, pluggable architecture, and broad ecosystem support.