HOW O.S IS VIRTUALLY HOSTED ON ANOTHER O.Sin computing, avirtual machine(VM) is anemulationof a particular computer system. Virtual machines operate based on the computer architectureand functions of a real or hypothetical computer, and their implementations may involve specializedhardware ,software, or a combination of both.Classification of virtual machines can be based on the degree to which they implement functionality of targeted real machines. That way,system virtual machines(also known asfull virtualizationVMs) provide a complete substitute for the targeted real machine and a level of functionality required for the execution of a completeoperating system. On the other hand,process virtual machinesare designed to execute a singlecomputer programby providing an abstracted and platform-independent program execution environment.Different virtualization techniques are used , based on the desired usage.Native executionis based on direct virtualization of the underlying raw hardware, thus it provides multiple "instances" of the samearchitecturea real machine is based on, capable of running complete operating systems. Some virtual machines can alsoemulatedifferent architectures and allow execution of software applications and operating systems written for anotherCPUor architecture.Operating systemlevel virtualizationallows resources of a computer to be partitioned viakernel's support for multiple isolateduser spaceinstances, which are usually calledcontainersand may look and feel like real machines from the end users' point of view.Some computer architectures are capable ofhardware-assisted virtualization, which enables efficient full virtualization by using virtualization-specific hardware capabilities, primarily from the host CPUs.

Question 1MS-DOS is a 16-bit operating system, with software available to utilize 32-bit features of the 80386 and later. Linux is a 32-bit and 64-bit operating system.

MS-DOS only has built-in support for single tasking. Linux was designed from the ground up for multitasking.

MS-DOS only supports one user. Linux supports multiple users.

MS-DOS is closed-source. Linux is open-source, available under the terms of the GPL.

MS-DOS is tied to the 80x86 platform. Linux can run on multiple architectures.