Configuration is the data that the proper functioning of an application relies upon. It is those bits of information that describe how things need to behave and helps control what code does. In other words, it configures the system to behave in a certain way with the expectation that it could also configure it to behave in a different way. To this end, configuration can be as simple as a toggle (turning something on or off) or as complicated as containing hundreds of parameters that describe an entire process.
The Drupal 8 configuration system is nothing short of a revolution in the Drupal world. It is not an improvement--it is a brand new way of thinking about managing configuration. Previously, there was no configuration management ...
