The first step to extend Drupal is to create a custom module. Although the task sounds daunting, it can be accomplished in a few simple steps. Modules can provide functionalities and customizations to functionalities provided by other modules, or they can be used as a way to contain the configuration and a site's state.

In this recipe, we will create a module by defining an info.yml file, a file containing information that Drupal uses to discover extensions, and enabling the module.