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.

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.

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

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.

Drupal Console provided a command line utility for performing common site administration tasks, code generation scaffolding, and a Read-Evaluate-Print-Loop for interacting with your Drupal site.

It is no longer actively maintained. Use Drush instead.

Symfony is a set of reusable PHP components, and a framework for building PHP applications. Drupal makes use of various Symfony components.

Performance and scalability determine how fast your application can serve a page and to how many users at a time.

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.

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

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.

Caching in Drupal is controlled by Drupal's Cache API which is used to store any type of data on a permanent or temporary basis. Some types of data tend to take a long time to compute, but utilizing the Cache API in your module can help your site load data more quickly.

Events are one of the ways that module developers can alter or extend Drupal without modifying existing code.

Controllers are the portion of a Drupal module that handle responding to an incoming request with the appropriate response data.