HTML and XHTML documents consist of text, which defines the content of the document, and tags, which define the structure and appearance of the document. The structure of an HTML document is simple, consisting of an outer <html> tag enclosing the document head and body:
 The structure of an XHTML document is slightly more complicated, as we detail in Chapter 16.
<html> <head> <title>Barebones HTML Document</title> </head> <body> This illustrates, in a very <i>simp</i>le way, the basic structure of an HTML document. </body> </html>
Each document has a head and a body, delimited by the <head> and <body> tags. The head is where you give your document a title and where you indicate other parameters the browser may use when displaying the document. The body is where you put the actual contents of the document. This includes the text for display and document-control markers (tags) that advise the browser how to display the text. Tags also reference special-effects files, including graphics and sound, and indicate the hot spots (hyperlinks and anchors) that link your document to other documents.