If your website ends in .html or .htm then you have a static Html website.  When websites were 1st developed this was the only type of webpage.  Modern website get most or all of their content from database-driven webistes.  These are called Dynamic websites.

Dynamic webistes usually have pages with file exentsions ending in .asp, .php, .aspx or .cfn.  For example http://www.yourdomain.com/page.asp?ID=1. 

Perma-link websites

An even more recent type of webpage has no file extension.  This is called perma-links.  A perma-link webiste page will look like this, http://site-ninja.com/my-google-pagerank.  Notice how keywords are separated by a dash to make the URL of the page.  Google has been directing more visitors to websites that have the keywords built into the name of the page, so if your website doesn't use keywords in the URL of the page, you are missing potential visitor traffic from Google and other Search Engines.

Downside of Html

1. Content can only be changed by a Webmaster, which means ongoing expense
2. Content seldom changes because of expense, which can prevent good Google Ranking.  Google want to direct traffic to sites with updated content.
3. Does not support a Blog or shopping cart

Upside of using a Content Management System “CMS”

1. You have full control to modify your website's content for FREE
2. A good CMS meets programming and Google guidelines
3. Test your website for standards at http://validator.w3.org
4. A good CMS will allow you to modify the most important keyword phrases in these areas, Meta Title, Meta Description, Perma-links, Heading Titles, Alt Text on photo, embedded videos.
5. All the areas mentioned above are more important than the words in any paragraph on the page.

Summary

1. If your website uses Html page or Dynamic pages that do not have keywords as part of the webpage address, then you are missing potental traffic from Search Engines.
2. The higher cost of a good Content Management System is quickly offset by your ability to update the site for FREE. 
3. Because you have the ability to update your site anytime, you are more likely to add new content.  Google rewards websites that have new content by directing visitors to your website.

Article written by Michael Kramer, Ameravant Web Design