The document body is the meat of the matter; it's where you put the contents of your document. The <body> tag delimits the document body.
Within HTML 4 and XHTML, the <body> tag has a number of attributes that control the color and background of your document. Various browsers have extended the tag to give even greater control over your document's appearance.
Anything between the <body> tag and its ending counterpart, </body>, is called body content. The simplest document might have only a sequence of text paragraphs within the <body> tag. More complex documents might include heavily formatted text, graphical figures, tables, and a variety of special effects.
Since the position of the <body> and </body> tags can be inferred by the browser, they can safely be omitted from an HTML, but not an XHTML, document. Like the <html> and <head> tags, we recommend that you include the <body> tags in your HTML documents, too, to make them more easily readable and maintainable.
The HTML and XHTML standards define a special type of document in which you replace the <body> tag with one or more <frameset> tags. This so-called frame document divides the display window into one or more independent windows, each displaying a different document. We thoroughly describe this innovation in Chapter 11.