In this chapter, you became familiar with cluster stacks and cluster stack layers. Each cluster stack layer was explained in detail by elaborating on the tasks it must provide and how to provide them. You also learned about the cluster software stack solutions that will be presented in practical examples in the following chapters of this book, and the necessary preparations and recommendations before installing the cluster software stack. In the next chapter, you will prepare the operating system to run the cluster stack software. You will follow step-by-step instructions on how to install and configure operating system requirements and cluster communication software.