VM for Virtual Machine is a software or operating system that displays the behavior of a physical computer, but is also capable of performing tasks such as running applications and programs.
Each virtual machine has virtual devices that provide the same function as the physical hardware and are of additional interest in terms of portability, manageability and security. One VM can be summed up as an illusion of a computing device.
One of the advantages of the virtual machine is that it is able to evade the characteristics of the physical machine, thus allowing a high degree of portability for software.