All HTML documents start with the <html> tag and ends with the </html>. Inside of the <html> tags you have the <head> and the <body>. The <head> tag contains the title (<title>) of the page and any JavaScript programs (<script>). It also contains any META tags (<meta>) which are used to denote the author or a description of the page. Everything in the <head> tag apart from the the title is not visible unless you view the source.
The <body> tag contains every thing in the page which you can see. These include images (<img>), links (<a>), tables (<table>) and the written text.
To view the layout of HTML just right-click anywhere on this page and click view source.