By Default we have two content types: Article and Basic page.
Which module creates those 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.