Client/Server
- The basic idea in client/server systems (like the Internet) is that typically the client makes a request of the server, who processes the request and returns the requested resource.
- The client connects to the server (host) using a specific port (i.e. 80 for HTTP, 110 for POP3).
- The server accepts connections from clients.
- Once the connection is established, communication is done through streams with standard I/O
calls.