In this chapter, we learned that Docker can be used on most operating systems and that the installation process varies a lot depending on the OS. We had our first interaction with the Docker daemon and launched our first container in Docker. Even though all the container did was write a command, that's how easy it is to start and run something inside a guest operating system.
We have also introduced the theme that shows what this book is all about, running a multicontainer web app of a web server container and a MySQL container: your own PaaS.
In the next chapter, we will further explore Docker, its terminology, and the community around it.