Some of the Drupal configuration settings are stored by default in the database - views, site variables, panels, or custom fields. The handling of these elements is tricky when it comes to a site in production. With the Features module, a developer can group the associated parameters and export them to the code. The exported code is downloaded as a module called a "feature" and added to the database - and can be moved between servers, allowing revisions to be tracked. A revolution for teamwork on Drupal projects!