There are two basic types of URLs – Static and Dynamic. Dynamic pages are templates where the database query results are displayed. These pages have a different URL for each result. URLs are generated according to the database query that was used. These are called as Dynamic URLs. Static URLs are the ones that are written and coded in the HTML code. These create static pages.
In terms of SEO, static URLs are very easily crawled and indexed by search engines. Dynamic URLs pose certain challenges for the search engines. Mainly because, the content and the URL are not constant. Indexing becomes very difficult in case of dynamic links due to the fact that keywords cannot be incorporated in the links. Very advanced search engines like Google are able to index dynamic pages with some efforts, but it is best to have static links for assured results. If your website is built with dynamic links architecture, for SEO purposes – maintain at least one significant page with a static URL.
Another workaround would be to get a static link to inconspicuously redirect to the dynamic URL. Web servers such as Apache has the mod_rewrite facility to achieve this!