A hypervisor is a type of computer software, firmware, or hardware that creates and runs virtual machines. It allows one host computer to support multiple guest virtual machines by virtually sharing its resources, such as memory and processing. The physical hardware, when used as a hypervisor, is called the host, while the many virtual machines that use its resources are guests. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources.

There are two types of hypervisors:

• Type 1 hypervisor: Also known as a native or bare-metal hypervisor, it runs directly on the hosts hardware to manage guest operating systems. It takes the place of a host operating system, and VM resources are scheduled directly to the hardware by the hypervisor. This type of hypervisor is most common in an enterprise data center or other server-based environments.

• Type 2 hypervisor: Also known as a hosted hypervisor, it runs on top of a host operating system and is used for end-users and software testing, where higher latency is less of a concern.

Hypervisors are the underlying technology behind virtualization or the decoupling of hardware from software. They make cloud-based applications available to users across a virtual environment while still enabling IT to maintain control over a cloud environments infrastructure, applications, and sensitive data. Hypervisors provide an option to continue running software by virtualizing the hardware environment required, allowing organizations to maximize resource usage on physical computers.