What makes Drupal powerful is only partly the functions included in a standard installation. The real power lies in the possibility to extend and customize these functions by using modules. These are plugin programs which alter the behaviour of your Drupal site.

This chapter summarizes how you find, assess, install and update modules.

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