VNC is platform-independent – a VNC viewer on one operating system may connect to a VNC server on the same or any other operating system. There are clients and servers for many GUI-based operating systems and for Java. Multiple clients may connect to a VNC server at the same time.
For connecting to remote desktop of another computer (via internet or network) and controls. Also connecting to VNCServer through Repeater or directly to VNCServer and a lot of other configuration options. For more details VNCServer