Before plowing through the examples in the next several lessons, you should have an understanding of some networking basics. Also, to boost your confidence, we've included a section that reviews what you may already know about networking in Java without even realizing it.
If you've been working on the other trails in this tutorial, you've probably loaded an applet over the Internet by now, and you've likely loaded images from the network into applets running over the network. All of this is using the network and you already know how to do it. This page highlights the networking features that are covered in other trails and lessons of this tutorial--features that you might already be familiar with--and provides links to the pages that discuss those features.
You'll learn what you need to know about TCP, UDP, sockets, datagrams, and ports to get the most out of the remaining lessons in this trail. If you are already familiar with these concepts, feel free to skip this section.