1.2.1.8 Virtual Machines

Question 1

What is a Virtual Machine?

Answer 1

• Any instance where software is used to take on the function of a machine, including intermediate code or running an operating system within another.
• A Virtual Machine is a theoretical computer in that it is a software implementation of a computer system. It provides an environment with a translator for intermediate code to run.

Question 2

What is Intermediate Code?

Answer 2

• Code partly translated between high-level and machine language produced by a compiler.
• Code that is halfway between machine code and object code is called intermediate code.
• This is independent of the processor architecture so can be used across different
  machines and operating systems.

Question 3

What are Virtual Machines used for?

Answer 3

• Virtual machines are commonly used to create a development environment for
  programmers to test programs on different operating systems.

-The advantage of this is that it saves both the time and money of having to purchase multiple devices solely for testing.

• However, running intermediate code in a virtual machine can also be considerably
  slower compared to running low-level code on the device it was designed for.

Question 4

Advantages of Virtual Machines?

Answer 4

• Protection from malware:

Malware will affect the virtual machine rather than the device being used.

• Running incompatible software:

Programs specific to different operating systems or different versions of an
operating system can be run within a VM, saving time and money required
to purchase the hardware.

A common example is of games consoles being implemented on PCs via a
virtual machine.