If the last decade has taught IT professionals anything, it’s that hardware is no longer the limiting factor it once was. A single rack of servers can host hundreds of workloads, and you can spin up an entire application stack in the cloud with a few clicks. Virtualization and cloud computing are the technologies that make this possible. They abstract physical resources into flexible, software-defined pools that you can allocate on demand, scale up or down at will, and manage through a web interface instead of a screwdriver. In this chapter, we’ll demystify both concepts, explore how they complement each other and show you how to deploy them securely and efficiently.