Programmatically delete configuration - Drupal 8
By default Drupal stores all configuration into database. Below example shows how to remove / delete configuration object of 'automated_cron.settings', i.e. remove cron settings.
Programmatically install / uninstall module - Drupal 8
Modules are used to extend and customize Drupal Core. To install module normally we can navigate to "Admin => Extend" link in toolbar.
Like older versions of Drupal, Drupal 8 doesn't allow modules to be enable / disable.