Last updated November 10, 2015. Created on May 16, 2012.
Edited by ashish_nirmohi, Itangalo. Log in to edit this page.

At a large scale, Drupal does three things when a page on your website is requested. The first is that Drupal checks which files and libraries are necessary to collect the information on the page – and how much of the information the requesting user is allowed to access. The second is to actually collect all the information, which usually involves quite a bit of querying and poking in the database. The third and final step is to take the big, naked array of collected data and dress it up with different templates and HTML tags to make it presentable in a web browser.

The last step is called Drupal's theme layer and is governed by your site's theme. The theme layer is separated from the rest of the data management. This means a website can have its look and feel completely changed without having to change the content a bit. For anyone skilled in HTML, CSS, JavaScript and other languages used to present digital content, it also means the possibility to do an extreme makeover of Drupal's presentation.

TIP: Most Drupal themes outputs (X)HTML, but nothing in Drupal forces the content to be presented as a web page. A theme could for example present content as spoken text, or as XML files processed by other applications.

The initial version of this section of the Community Documentation came from the book Drupal 7: The Essentials, courtesy of NodeOne and Johan Falk.

Looking for support? Visit the Drupal.org forums, or join #drupal-support in IRC.