Masthead Goes Here
id="masthead"

This is an H1 Title

This is a simple DIV demo. The content in paragraph format goes here. The H1 tag above and the P tags are within the <div id="content"> section, which is defined in the stylesheet.

The black border with a gray shadow around the entire page are within:
<div id="wrapper">  This div immediately follows the <body> tag.

HTML 5 replaces <div id="masthead"> with <header>
HTML 5 replaces <div id="content"> with <main>
HTML 5 replaces <div id="footer"> with <footer>
HTML 5 does not have a wrapper element. So use <div id="wrapper">

Right-click to View Source and see the simple DIV structure.