Virtualization uses specialized software called a hypervisor to create multiple cloud instances or virtual machines on the same physical computer.
Comparing cloud instances and virtual machines
After you install virtualization software on your computer, you can create one or more virtual machines. You can access virtual machines the same way you access other applications on your computer. Your computer is called a host, and a virtual machine is called a guest. You can have more than one guest running on the host. Each guest has its own operating system, which can be the same or different from the host operating system.
From the user’s point of view, the virtual machine runs like an ordinary server. It has settings, configurations, and installed applications. Computing resources, such as central processing units (CPUs), RAM, and storage, look the same as on the physical server. You can also configure and update guest operating systems and their applications as needed without affecting the host operating system.
Hypervisors
A hypervisor is virtualization software that is installed on physical computers. It is a software layer that acts as an intermediary between virtual machines and the underlying hardware or operating system of the host. Hypervisors coordinate access to the physical environment so that multiple virtual machines have access to their own share of physical resources.
For example, if a virtual machine requires computing resources, such as computer processing power, the request is first sent to the hypervisor. The hypervisor then passes the request to the underlying hardware, which performs the task.
Below are two basic types of hypervisors.
Hypervisors of the first type
Type one hypervisors, also called hypervisors without an operating system, run directly on the computer hardware. They have some operating system capabilities and are very efficient because they interact directly with physical resources.
Type 2 hypervisors
Type two hypervisors run as an application on computer hardware with an existing operating system. Use this type of hypervisor when running multiple operating systems on the same computer.