Pathauto

The Pathauto Module for Drupal allows automatic defaults for URL paths. 

With this Module, paths can be set per Content Type.  For example, if a website has a listing of restaurants, the default URL path for any node created of the "restaurant" Content Type may be set to "restaurant/[title-raw]".  The Token module is used to place the desired path in the URL.  For example: the Token [title-raw] refers to the Node Title.  The resulting URL for any Node created with the "restaurant" Content type would be "sitename.com/restaurant/node-title".  Pathauto can also control Category URL's for use with content categorized with Taxonomy. 

The Pathauto module if very flexible and has a wide range of configuration settings.  This Module is very helpful, especially for larger Drupal sites, sites with user generated content, or systems that are updated by those with little or no Drupal knowledge.