Virtualization is the process of running powerful software on a computer to create a complete environment that imitates all of the hardware you’d have on a real computer. In this virtual environment we can install and run an operating system exactly as if it were installed directly on its own hardware. That guest environment is called a virtual machine. Virtualization convinces an operating system that it’s running on its own hardware.
Virtualization enables one machine, called the host, to run multiple operating systems simultaneously, full virtualization requires an extra layer of programming called a hypervisor to manage the vastly more complex interactions. A hypervisor has to handle every input and output that the operating system would request of normal hardware. Now you can easily add and remove virtual network cards, virtual hard drives, virtual RAM and so forth. Virtualization even goes so far as to provide virtualized BIOS and system setup for every virtual machine.
The host machine allocates real RAM and CPU time to each running virtual machine. You can run a number of virtual machines at the same time, but do you homework first and make sure you will have enough CPU power and more importantly, enough RAM.
Here is how Wikipedia describes Hyper-V
Microsoft Hyper-V, codenamed Viridian and formerly known as Windows Server Virtualization, is a native hypervisor; it can create virtual machines on x86-64 systems running Windows. Starting with Windows 8, Hyper-V supersedes Windows Virtual PC as the hardware virtualization component of the client editions of Windows NT. A server computer running Hyper-V can be configured to expose individual virtual machines to one or more networks. Hyper-V was first released alongside Windows Server 2008, and has been available without charge for all the Windows Server and some client operating systems since.
In the BIOS, the following features must be supported:
Second Level Address Translation (SLAT)
Hardware-based Data Execution Prevention (DEP)
In Windows, Hyper-V must be enabled and running.
You have to be a member of the local Hyper-V Administrators group.