Here is an interesting website that takes your URL, analyzes the html code and creates a visualization. You can see what makes up your page: links, tables, etc.
Here is a graphic for the CDE website front page: distance.uaf.edu
blue: for links (the A tag)
red: for tables (TABLE, TR and TD tags)
green: for the DIV tag
violet: for images (the IMG tag)
yellow: for forms (FORM, INPUT, TEXTAREA, SELECT and OPTION tags)
orange: for linebreaks and blockquotes (BR, P, and BLOCKQUOTE tags)
black: the HTML tag, the root node
gray: all other tags
Try this with your favorite website or with one that you are working on to see what it looks like.