wondering

how do you create a webpage with no extension?

rookie web kitty here and was just thinking of how the pages don't end in .*

the url might not be excatcly the file you are viewing
redirecting and url rewriting 101

If you're using Apache:
http://httpd.apache.org/docs/current/rewrite/

Software like Drupal/Wordpress commonly has a root level "index.php" which handles all incoming requests. Rewrite rules will redirect "pretty" URLs to this page. For example:

<Directory /var/www/example.com>
   RewriteEngine on
   RewriteBase /
   RewriteCond %{REQUEST_FILENAME} !-f
   RewriteCond %{REQUEST_FILENAME} !-d
   RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]
</Directory>