* This material is now outdated as the CMI system no longer stores to files by default but instead saves to the database in specialized CMI tables. We are working on updated Drupal 8 material and CMI is one we are covering.
One thing in Drupal 7 that people have a love-hate relationship with is the Features module. Features gives you the means to export database-stored site settings in code that you can put into version-control and move from server to server. In Drupal 7, when using Features to make a change to your Drupal site configuration settings, you need to update the feature or make sure the settings are in a feature and (re)create them. When deploying, you revert your features so your site settings match what is in code.