Creating a TCP/IP connection on already-networked computers

[John Salerno]

Grant Edwards wrote:

> If the two computers are in no way connected via any type of
> network, then the two programs won't be able to talk to each
> other.
> 
> The programs can't create a network, they can only use one that
> already exists.

But isn't that the point of the program, to create a network between the 
two computers? Isn't that what the host and port are used for, to open a 
connection?

(Just to clarify, when I say "in no way connected", I don't mean not 
connected to the internet in general. I know they need access to the 
internet for any kind of networking program to work at all.)