Use the Configuration API to access configuration data stored by a module, provide default configuration, create settings forms, and other tasks such as overriding settings for a local environment.

The Git version control system can help you keep track of changes in your codebase and make sure you don't unintentionally lose work.

Keeping a Drupal site secure requires monitoring security announcements, performing regular updates, and knowing how to properly use Drupal’s APIs to write secure code.

The Drupal Composer Project provides a scaffold for starting a new Drupal project and managing that project's dependencies with Composer. It was created before the drupal/recommended-project Composer project template was developed, which is the current best practice method for creating a new Drupal site with Composer.

HTML and CSS are the foundational languages for how browsers display web pages.

YAML, which stands for YAML Ain't Markup Language, is a human-readable data serialization format that's been widely adopted in a variety of use cases in Drupal.

Debugging your Drupal codebase can be made substantially easier by learning how to enable and configure the Xdebug PHP extension.

Learn about resources to guide you through the process of updating a module or theme to the latest version of Drupal.

The Migrate API can be used to import content from an older Drupal site (Drupal 7 or older), or any other data source, into the current version of Drupal.

Themes provide the HTML, CSS, JavaScript, and other assets that are responsible for the look and feel of your site.

A module is a set of PHP, JavaScript, and/or CSS files that extends site features and adds functionality. The Drupal core software comes with a set of modules that provide a range of features.

Web services allow two or more applications to share data and instructions with one another across the Internet.

PHP namespaces provide a way in which to group related classes, interfaces, functions and constants. Drupal uses PSR-4 namespaces to autoload the correct PHP class from a file, accommodating variations in site structures.