HTML & XHTML: The Definitive Guide, 6th Edition

Chapter 3. Anatomy of an HTML Document

Most HTML and XHTML documents are very simple, and writing one shouldn't intimidate even the most timid of computer users. First, although you might use a fancy WYSIWYG editor to help you compose it, a document is ultimately stored, distributed, and read by a browser as a simple text file.^[*] That's why even the poorest user with a barebones text editor can compose the most elaborate of web pages. (Accomplished webmasters often elicit the admiration of "newbies" by composing astonishingly cool pages using the crudest text editor on a cheap laptop computer and performing in odd places, such as on a bus or in the bathroom.) Authors should, however, keep several of the popular browsers on hand, including recent versions of each, and alternate among them to view new documents under construction. Remember, browsers differ in how they display a page, not all browsers implement all of the language standards, and some have their own special extensions.

Appearances Can Deceive

Documents never look alike when displayed by a text editor and when displayed by a browser. Take a look at any source document on the Web. At the very least, return characters, tabs, and leading spaces, although important for readability of the source text document, are ignored for the most part when displayed by an HTML/XHTML browser. There also is a lot of extra text in a source document, mostly from the display tags and interactivity markers and their parameters that affect portions ...