Drupal modules

Drupal module is a packaged set of files (usually PHP and CSS) that adds or modifies existing features and functionality. Modules can be considered as plug-ins, extensions, or add-ons that extend Drupal core.

There are two main types of modules: Core and Contributed.

Core modules are included in the default Drupal install and are located in the main “modules” folder in the root directory of the Drupal install. These modules codes must be never edited, but settings for core modules can be changed in the Drupal admin interface.

Contributed modules modify the features that are currently included in Drupal core. These are modules that have been created by users in the Drupal community, their code is available for use via the Projects section in Drupal. These modules are placed within the “sites” folder instead of the main “modules” folder in the root directory of the Drupal install.