It's a good guess that you're reading this book because you want to learn how to use XML (Extensible Markup Language). If you are like me, you want to pick up a computer book and start writing code by at least the second or third page. You've probably heard all the hype about how XML will change the Web and bridge gaps among the world's various types of digital information. You're convinced that XML is something you need to learn, and you might be anxious to jump right in and start coding. If you are that type of person, you won't have to wait too long. We'll get into some XML code before the end of the second chapter. But to really understand XML—and after all, that is the goal—you could probably benefit from some background information. These first few chapters provide a framework for the rest of the book—in addition to getting us into a little code. After reading these chapters, you should have a better understanding of and appreciation for XML. Establishing a framework is especially important with XML for a couple of reasons:
In many ways, XML represents a fundamental shift in the way information is delivered on the Web. While XML might not be as "flashy" as some of the other new Web technologies, it has the potential to have as much impact on Web delivery as HTML did several years ago. In this chapter, you'll begin to see why an extensible language like XML is necessary. We'll look at a brief background of text markup and how it works. We'll also examine differences between some of the more common markup languages.