With Drupal 8 you can synchronize staged configuration changes with the currently active configuration. The synchronize page can be found at <strong>Menu > Configuration > Development > Configuration management</strong> (<code>admin/config/development/configuration</code>).

The synchronize page will list all the changes between the config files in the <strong>active</strong> and <strong>staging</strong> folder within the config storage, located in the <code>sites/default/files/config_HASH/</code> folder (default). From this list you can view the differences between each of the config files to ensure that the changes are as expected.  

The listing will also show <strong>new or removed</strong> config files.  It is important to check that there are no removals of any core config files (such as system.*, entity.*) as this will result in a site error.

<h3>Example</h3>

<ol>
  <li>Install Drupal</li>
  <li>Export the full site configuration at <code>admin/config/development/configuration/full/export</code>. This will create in a zip file.</li>
  <li>Unzip and edit the site name in the <strong>system.site.yml</strong> config file</li>
  <li>Copy the entire set of unzipped files into the <code>sites/default/files/config_HASH/staging</code> folder</li>
  <li>Then go to the synchronize config page <code>admin/config/development/configuration</code> and the list will contain an entry for <strong>system.site</strong></li>
  <li>Select 'View differences' to see the changes between the active and staging version of the config file</li>
  <li>To import and set the change to active, select 'Import all'</li>
</ol>