Oracle VM VirtualBox, formerly a product of Sun Microsystems. The application is installed on the current host system. Apart from host operating system, virtual box enables the user to install and use additional guest operating system, known as Guest OS, with their respective virtual environments.
Virtual Box supports various host operating systems like Windows 8, Windows 7, Windows Vista, Windows XP, Mac OS, Linux, and Solaris. Guest Operating systems include different versions of Windows, Solaris, Linux, OS/2, BSD and many more.
VirtualBox is released with new versions frequently with better options and features. Oracle encourages contributions by others to increase the quality of its product.
The following video clip will give you an idea how to use virtual box: