Static URLs and Dynamic URLs

The search engines treat static URLs differently than dynamic  URLs.

Static URLs 
Static URLs means  not add a query string.
By this definition, a URL referencing a PHP script without
parameters is still static.
 examples of static URLs :

Dynamic URLs
Dynamic URLs are  that add a query string, add  by ?.
 This string is used to pass various parameters to a script.

Static URLs can be converted to DynamicURLs with the .htaccess