VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures.
So you stayed here? Oh amazing, but okay.
I also assume that you have some basic knowledge about computers, and you know how to unpack tar or zip files. Edit text files etc. in the what ever OS you are using. This document describes the situation where you sit at your window$ box and actually works on your linux box through the use of VNC.
But VNC is not limited to this situation. Visit the VNC homepage for further examples.