You can also switch off the stylesheet in your browser preferences to view a simple version of the site.
This way, you can override the main stylesheet templates, and hence your changes will affect the overall styling of your document.
Finally, within the html file where this stylesheet is being used, everything within the "div" tags that call this element are formatted as defined above.
The stylesheet defines the margins, formatting, and placement of those columns.
If you are using CSS, this is also where either the <STYLESHEET> information would go or where you would reference an external stylesheet.