The configuration API is one of the most important topics a Drupal 8 developer needs to understand. There are many aspects to it that tie it into other subsystems, so it is critical to be able to both use and understand it properly.
In this sub-chapter, we will cover a lot about the configuration system. We start by understanding what configuration is and what it is typically used for. Then, we will go through the different options we have for managing configuration in Drupal 8, both as a site builder and a developer using the Drush commands. Next, we will talk about how configuration is stored, where it belongs, and how it is defined in the system. We will also cover a few ways in which configuration can be overridden at different levels. Finally, we look at how we can interact with a simple configuration programmatically. So, let's begin with an introduction...