A virtual machine (VM) is a software emulation of a physical computer system that allows multiple operating systems (OS) to run on a single physical host machine. Each VM operates as if it were a standalone computer system, with its own CPU, memory, network interface, and storage, but all resources are shared from the physical host machine.
Virtual machines are created using virtualization software that partitions the physical host machine's resources into multiple isolated environments. Each VM can run a different operating system, allowing for a variety of different applications and services to run on the same physical host machine. This allows for greater utilization of hardware resources, reduced power consumption, and improved flexibility and scalability compared to running multiple physical machines.