Hyper-V is a virtualization technology built into Windows 8.x and above. Hyper-V allows you to create virtual machines on a Windows 8.x or above host machine. It is useful to demonstrate concepts such as AlwaysOn that require more than one machine for the setup.
In a real-world scenario, the availability group replicas are either physical boxes or on-premises or cloud VMs sized to run Online Transactional Processing (OLTP) workloads as per business requirements.
Note
A host machine is the one that will host or contain the virtual machines created as part of this lesson's exercises. Almost all of the PowerShell scripts specified here are to be run on the host machine unless otherwise specified. The host machine should be a physical machine and not a virtual machine. If you plan to use a virtual machine as the host machine, then install Windows Server 2016 and enable nested virtualization to carry out the demos. The PowerShell console should be run in the administrator role...