Concepts are only complicated when you don't find the right resource to explain them. This document presents the subject of developing software for the Internet in a way that anyone with some basic programming experience will understand. The basic principles covered include IP addressing, hostnames, services, TCP and UDP protocols, sockets and blocking versus non-blocking transfers. The report is further enhanced by a step-by-step tutorial in building an echo client and server application using Visual Basic and the free WINSOCK custom control, SocketWrench. 

Many thanks to the good people at Catalyst Development for allowing us to use this excellent TCP/IP tutorial. You can jump to the Catalyst Development website if you want to try out the step-by-step tutorial and build the echo client and server application or check out their products.