Drupal internal path versus url alias

The attached pdf document explains the difference between :

• a url
• a translated url
• a url alias, and
• Drupal’s internal path

In a nutshell, given that one types the following url in a browser’s address bar :

http://11heavens.com/Drupal-coder-lost-in-space/where-are-we

Based on rewrite rules found in the .htaccess file in the same folder as index.php, the server translates this url to :

http://11heavens.com/index.php?q=Drupal-coder-lost-in-space/where-are-we

The page index.php receives a name and value pair, where “q” is the name and “Drupal-coder-lost-in-space/where-are-we” is the value associated with that name.

Drupal looks up a url alias table — {url_alias} — and recognizes that this path is an alternate path for this Drupal’s internal path : node/44.

On the server, the page index.php builds its content based on that “internal path” and sends the xhtml back to the browser. In the browser is shown in full view the node with unique identifier 44.