Which module creates the "Article" and "Basic page" content types?
@Wim Mostrey was right.

In Drupal 7, the default configuration for modules (e.g. content types, field configuration, views) required custom PHP code to install and keep updated. In Drupal 8, these are stored with the configuration system in plain text YAML files, for example core/profiles/standard/config/install/node.type.article.yml. 

References


Include default configuration in your Drupal 8 module