The chapters in this book are arranged so that if you read them in order, you will face a minimum of cases where I have to say "you won't understand this part of the code, because we won't cover that topic until two chapters later." However, only some of what each chapter introduces is used in later chapters. For example, Chapter 3, "The LWP Class Model" lists all sorts of LWP methods that you are likely to use eventually, but the typical task will use only a few of those, and only a few will show up in later chapters. In cases where you can't infer the meaning of a method from its name, you can always refer back to the earlier chapters or use perldoc to see the applicable module's online reference documentation.