Pathauto and Redirect

Using permalinks makes the most sense on sites that use path aliases for their content (e.g. /news/opened-new-store-paris). Instead of providing those manually, which is perfectly possible, you probably want them to be autogenerated. This auto-generating functionality is however not a Drupal core feature but provided by the Pathauto module.

Once enabled, an alias provides a nice clean URL for a path on a site. However Drupal does not remove the old path (e.g. /node/123). The problem is that you now have two URLs representing the same content. This can get you penalized by the search engines. To avoid that, use the Redirect module. Although not mentioned on the project page, it checks the current URL for an alias and does a 301 redirect to it (just by enabling the module).