HTML and CSS Reference
Take note of just one more thing before you start actually writing web pages. You should
know what HTML is, what it can do, and most important, what it can't do.
HTML stands for Hypertext Markup Language . HTML was based on the Standard
Generalized Markup Language (SGML) , a much larger, more complicated document-
processing system. To write HTML pages, you won't need to know much about SGML.
However, knowing that one of the main features of SGML is that it describes the general
structure of the content inside documents—rather than its actual appearance on the page
or onscreen—does help. This concept might be a bit foreign to you if you're used to
working with WYSIWYG (What You See Is What You Get) editors such as Adobe's
Dreamweaver or Microsoft FrontPage, so let's go over the information carefully.
HTML Describes the Structure of a Page
HTML, by virtue of its SGML heritage, is a language for describing the structure of a
document, not its actual presentation. The idea here is that most documents have com-
mon elements—for example, titles, paragraphs, and lists. Before you start writing, there-
fore, you can identify and define the set of elements in that document and name them
appropriately (see Figure 3.1).
If you've worked with word processing programs that use style sheets (such as Microsoft
Word) or paragraph catalogs (such as FrameMaker), you've done something similar;
each section of text conforms to one of a set of styles that are predefined before you start