Which type of hypervisor is installed on top of an existing operating system?

A Type 2 hypervisor is installed on top of an existing operating system. This means that it operates as an application within the host operating system, leveraging the host's resources to manage guest virtual machines. This is distinct from a Type 1 hypervisor, which runs directly on the hardware without an underlying operating system, offering better performance and efficiency because it has direct access to the hardware resources.

Type 2 hypervisors are typically user-friendly and are often used for desktop virtualization scenarios where users want to run multiple operating systems on their personal computers without needing dedicated hardware resources for each. This makes them ideal for development, testing, and running applications that may require different operating environments simultaneously.

The terminology around hypervisors clarifies that there is no Type 3 hypervisor; generally, the classification includes only Type 1 and Type 2. The term "virtual machine manager" refers more broadly to any software that manages virtual machines, which can include both types of hypervisors. However, it does not specify the nature of their installation in relation to an operating system.