We begin by clarifying that with vnc does not mean a particular program, but a category of programs vnc that allow remote control of a computer.
The acronym stands for Virtual Network Computing vnc and the common feature is the use of such software RFB protocol, Remote Frame Buffer.
In this article we use a vnc server on a Linux system on a Windows system. The information provided will be helpful, however, in any case configuration.

The scheme is simple: on the one hand to control the computer on which to install the vnc server, the computer controlling the other hand using the client component,
the so-called viewer. The two machines can be connected via a private LAN or through the public Internet.
In the latter case the work is likely to be more burdensome for the need to configure other devices such as firewalls and routers.

If the workstation client establishes a connection to the server will see the desktop of the remote machine in a window of the program.
We can act on it directly with your keyboard and mouse as if we were our physically sitting at the computer.
The cool thing about this is that the operating systems involved in communication can be different: Linux, Windows or MacOSX.
We could control a Windows 2003 server on our Linux box, or, conversely, a Linux server from a Windows XP station.

More info at VNC: how to manage servers remotely
More info at VNC: how to manage servers remotely