I'm having a hard time getting the fundamentals down about these TCP Socket classes.

When you use TcpClient, you can set the IP Address or domain name to connect to the server end of the socket. I see examples that use "localhost" as the first parameter for TcpClient. Is this just a broadcast over the network to find the server that has a TcpListener listening on the dictated port of the second parameter of the TcpClient declaration? With any IP address for TcpClient (I realize that's an option, though), how does "localhost" find the TcpListener server?