Nested Hyper-V is a new feature in Windows 2016 and Windows 10 (Anniversary update and later). Nested Hyper-V enables a Hyper-V VM to host VMs which also have virtualization enabled. You could, for example, take a physical host (say, HV1) and on that host run a VM (say VM1). With nested Hyper-V, you could enable your VM1 VM to host VMs and create a nested VM inside it called Nested1.
Nested VMs have a number of uses. First, nested MVs hosted in one VM are provided hardware isolation from nested VMs run in other VMs. This provides a further level of security for virtual machines. It's also useful for testing and education/training. In a training course, you could give a student one VM and enable him to create additional VMs as part of the course. And most IT pros just find it cool! You could, for example, run all the recipes in this chapter...
