Drupal provides a wide range of modules that enable you to extend and customize its functionality. A basic Drupal installation contains a light-weight core set of modules. By installing additional modules from the vibrant community of Drupal developers, you can add all kinds of functionality to your site: comments, authentication, site analytics, and much more.
Drupal has two types of modules: core modules and contributed (also known as "contrib") modules.
Core modules, as their name implies, form the core of Drupal functionality. Most major features are built as a separate core module, so you can enable or disable them as needed. By starting with a minimal set of features, this helps enhance Drupal's stability, performance, and security.
Not all of the core modules are enabled by default. For example, you must enable the contact module if you want site visitors to be able to send e-mails to other authenticated users.
Core modules are stored in the core/modules directory where you installed Drupal. To view a list of the Drupal core modules, follow these steps:
The Drupal user community creates and maintains contributed (also known as “contrib”) modules. There is a large number of contributed modules available, and you should choose carefully which ones you need. Here are four important points to consider when evaluating contributed modules for possible use in your site:
Contributed modules are stored in the modules directory where you installed Drupal.
To view a list of contributed modules for Drupal 8, please visit https://www.drupal.org/docs/8/modules.
To view a list of contributed modules for Drupal 7, please visit https://www.drupal.org/docs/7/modules.