In this chapter, we’ll cover the basics of XML – essentially, most of the information you’ll need to know to get a handle on this exciting technology.After we’re done exploring some terminology and examples, we’ll jump right in and start working with XML documents.However, XML allows you to define your own set of tags. It’s much more flexible than HTML because it allows you to create your own custom tags.However, it’s important to realize that XML is not just a language.And all the code used in the book is available to customers in a downloadalbe archive.To find out more about “No Nonsense XML Web Development with PHP”, visit the book’s information page, or review the contents of the entire publication. If ever there were a candidate for “Most Hyped Technology” during the late 90s and the current decade, it’s XML (though Java would be a close contender for the title).
That’s why we need to give computers as much help as we can.I’ll try to stay away from the grandstanding hoopla that has characterized much of the discussion of XML; instead, I’ll give you the background and know-how you’ll need to make XML a part of your professional skillset. Whenever a group of people asks this question, I always look at the individuals’ body language.A significant portion of the group leans forward eagerly, wanting to learn more.Semantics and Other Jargon You’re going to be hearing a lot of talk about “semantics” and other linguistics terms in this chapter. For example, if I asked you to list as many names for “female animals” as you could, you’d probably start with “lioness”, “tigress”, “ewe”, “doe” and so on.If you were presented with a list of these names and asked to provide a category that contained them all, it’s likely you’d say something like “female animals.” Furthermore, if I asked you what a lioness was, you’d say, “female lion.” If I further asked you to list associated words, you might say “pride,” “hunt,” “savannah,” “Africa,” and the like.As always, you can download this excerpt as a PDF if you prefer. Whenever I talk about XML with developers, designers, technical writers, or other Web professionals, the most common question I’m asked is, “What’s the big deal?