What would a programmer use a virtual machine for?

Question

What would a programmer use a virtual machine for? I need to know for my assembly language class and I have been having problems understanding what a virtual machine is. I need to know what a virtual machine is and why a programmer would use one.

Answer 1

A virtual machine is made of several components, the main being that there is one main computer that has an operating system, usually a windows version xp, vista or above on it, or one of the many server versions of windows on it. This is the HOST computer. Spaces rather similar to partitions are carved out of the hard drive free space...Each of these will "host" or support a virtual machine, with it's own hard disk drive and swap space made out of whatever space was separated from the main system...Each of these virtual machines will run an operating system of its own, say any windows from 95 to 7 , completely in its own memory space and kernel protection mode...these virtuals can do anything the host is capable of, utilizing the same internet or network connections...with the main benefit being that

if one or more of them crashes for any reason, the Host computer remains unaffected !

That is the main and primary reason for using virtual machines, or even, in the case of many online games nowadays, virtual servers nested within one main host server. Of course, secondary reasons would be the ability to run one or more operating systems on a single computer AT THE SAME TIME...

Answer 2

A virtual machine is exactly what it sounds like, your machine takes part of its hardware power and reserves it for the virtual machine program (runs the virtual machine). The you can "run" the virtual machine and install an operating system and other programs on it. It is basically a computer inside a computer except its all virtual, no actual hardware.



It's purpose is plentiful. Virus companies use it to analyze viruses to find fixes. Malware companies use it to analyze malware. Even web hosters use it. They make a virtual machine with certain specs (based on what you pay) and give you access to it. The nice thing about virtual machines is that are isolated from the rest of the system unless you explicitly give them access.

Answer 3

Technically, a virtual machine is just an emulator, so you can run an operating system inside another operating system. Think of it this way, you turn on your computer which runs Windows 7, but you need to run Ubuntu. Instead of formatting and resizing your hard drive into multiple partitions (one of which has Windows 7, and the other has Ubuntu), you open an Ubuntu VM inside Windows 7 and you have what is essentially a full Ubuntu operating system without having to change a thing!



Now, I'm not going to give it all away, but what benefit would you get by having access to nearly any operating system or hardware setup on one computer when programming?

Answer 4

It is a small amount of memory reserved in a computer for another operating system.