What is a Virtual Machine
A Virtual Machine allows the user to run more than one operating system on a system and that too without dividing the memory for each i.e. one operating system is allowed to run inside another operating system. It means that one version of Windows can be run inside another version of Windows or one type of Operating System (say Linux) can be made to run inside another Operation System (say Windows).
The Virtual Machine holds a temporary memory of everything that happens and dumps the memory when the session is closed while physical machine keeps a permanent or semi-permanent memory of it.
Virtual Machines, now- a- days, are used at a very large scale. Whether it is a college going student or a technical person, the Virtual Machines are used by number of people. Earlier the Virtual machines were limited to technical positions (in the companies) only.
Virtual Machines allow the programs to run under multiple instances of operating systems. For example: If a program is going through testing phase of the software development life cycle, the tester need to debug the program in other operating systems too (as the customers can use any of the operating system, depending upon their choice). Installing different – 2 operating systems on different machines is not feasible for the technician and the company as well, so the Virtual Machines plays a very important role in these type of situations.
One main advantage of Virtual Machine is that it’s one of the by- products is that the two systems can be entirely separated from each other and this allows the user a good level of security which is very essential and cannot be matched.
Virtual Machines are of two types:
System virtual machines – contains all standard features of Operating System. Process virtual machines – are designed to carry out a specific function.
Virtual Machines are used to isolate one application from another as the applications often interfere with each other and cause problems.
Virtual Machines can be moved from one physical machine to another i.e. these are portable. The user only has to transfer the virtual machine disk file to the physical machine on which he or she has to move virtual machine, as virtual machines store information in a single file only.
Virtual machines are essential because they allow different applications to run simultaneously and save the resources as they are hosted on a single physical device.