There are a number of different virtualization technologies available under the Ubuntu Server. In this section, we will discover the virtualization concept in general with its different technologies and approach. Then, we will study some of the most popular virtualization programs, such as Kernel-based Virtual Machine (KVM), XenServer and Docker, with one program from each technology.
Virtualization is used to run one or more operating systems / applications as a simple software on one or more computers/servers instead of not being able to install more than one operating system per machine. These virtual machines are called VMs, environments, and even VEs. The virtualization of operating systems (OS) is a technique that allows you to run multiple OSes simultaneously on a single computer as if they were working on separate computers.