1 Introduction
Sun VirtualBox is a collection of powerful virtual machine tools, targeting desktop
computers, enterprise servers and embedded systems. With VirtualBox, you can virtu-
alize 32-bit and 64-bit operating systems on machines with Intel and AMD processors,
either by using hardware virtualization features provided by these processors or even
entirely in software, at your option.
Youcan find a brief feature overview in chapter 1.3,Features overview, page 13; see
chapter 12,Change log, page 155 for a detailed list of version changes.

1.1 Virtualization basics

With VirtualBox, you can run unmodified operating systems – including all of the
software that is installed on them – directly on top of your existing operating system,
in a special environment called a “virtual machine”. Your physical computer is then
usually called the “host”, while the virtual machine is often called a “guest”.
The following image shows you how VirtualBox, on a Linux host, is running Win-
dows Vistaas guest operating system in a virtual machine window:
VirtualBox allows the guest code to run unmodified, directly on the host computer,
and the guest operating system “thinks” it’s running on a real machine. In the back-
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