Virtual Server 2005 is a software that allow you to create "several virtual computers" within your operating system.
Virtual Server is a software that allows you to run several operating systems (including Microsoft Windows Server™ 2003 and Microsoft Windows 2000 Server) simultaneously on a single physical computer.
The computer on which you install 'Virtual Server' is called 'Host Computer'. The Host Computer must be a high configuration computer with several GB memory, lot of hard disk space and high power CPU so that it can run several virtual machines within it.
Host Operating System
The operating system installed on your host computer is called 'host operating system'.
Each virtual computer you create within the Virtual Server software is called Virtual Machine or Virtual Computer.
Guest Operating System
The operating system installed on your virtual computer is called 'guest operating system'.
You can create several virtual computers within Virtual Server software. All you have to do is, login to Virtual Server, create a virtual computer and that is it ! You have a brand new computer for you! Each computer you create within the Virtual Server will be a (almost) fully functional computer, even though they exist only within the software.
Your new virtual computer is a blank computer (created using software). It has it's own memory (taken from the host computer), hard disk (internally, it is a single file saved in your host computer), network card (shared with host computer), and access to all other hardware units attached to your host computer. The virtual machines can connect to network and internet.
When you create a virtual computer, it is a brand new computer. It has no operating system installed and hard disk is not partitioned or formatted. For each virtual server you create, you have to do everything that you do for a new computer.
All virtual machines you create using the Virtual Server 2005 software are fully functional computers. You can partition the hard disk, format, install operating systems and any software you want. Even though they are virtual computers, you can use it just like any other computers. All you have to do is, start host computer, run Virtual Server 2005 software, view the list of created virtual machines and start the one you want. You will see the virtual machine within a window inside the Virtual Server 2005 software.