According to Wikipedia:
VNC by default uses TCP port 5900+N, where N is the display number (usually :0 for a physical display). Several implementations also start a basic HTTP server on port 5800+N to provide a VNC viewer as a Java applet, allowing easy connection through any Java-enabled web browser. Different port assignments can be used as long as both client and server are configured accordingly.
My book says when you start vncserver for the first time (versus starting multiple instances) you use
It refers to connecting to display number 1 and port 5901.
What happens if you connect to 5900 (Physical display), does this cause problems? When they say physical display, do they mean your monitor? If so, what happens if you connect to it? I realize you can change these ports anyway, but in the context of Wikipedia with default configuration, let's say you connect to