Object-oriented PHP utilizes classes and objects to organize code into reusable chunks. This approach helps us organize complex applications, such as Drupal, into modular code called classes that can be reused across the entire system.

Composer is the preferred dependency management solution for PHP, is used by Drupal core, and is becoming increasingly popular for managing the modules and themes used for a Drupal project.

Upgrading is the process of moving your site from a previous major version of Drupal to a newer version, for example from Drupal 7 to Drupal 11.

As an open source project, Drupal depends on community contributions in many forms including documentation, code, translation, speaking, organizing events, mentoring others, and even donating money.

A reliable backup will allow you to restore your site if something goes wrong.