PathAuto is a Drupal module that allows to automatically create path aliases for different type of pages.
The Pathauto module automatically generates path aliases for various kinds of content (nodes, categories, users) without requiring the user to manually specify the path alias. This allows you to get aliases like /category/my-node-title.html instead of /node/123. The aliases are based upon a "pattern" system which the administrator can control.
Pathauto depends on the Token module.