# Exporting and Importing Configuration

Drush provides commands to export, transfer, and import configuration files
to and from a Drupal 8 site.  Configuration can be altered by different
methods in order to provide different behaviors in different environments;
for example, a development server might be configured slightly differently
than the production server.

This document describes how to make simple value changes to configuration
based on the environment, how to have a different set of enabled modules
in different configurations without affecting your exported configuration
values, and how to make more complex changes.

## Simple Value Changes

It is not necessary to alter the configuration system values to 
make simple value changes to configuration variables, as this may be
done by the [configuration override system](https://www.drupal.org/node/1928898).

The configuration override system allows you to change configuration
values for a given instance of a site (e.g. the development server) by
setting configuration variables in the site's settings.php file.
For example, to change the name of a local development site:
```
$config['system.site']['name'] = 'Local Install of Awesome Widgets, Inc.';
```
Note that the configuration override system is a Drupal feature, not
a Drush feature. It should be the preferred method for changing
configuration values on a per-environment basis; however, it does not
work for some things, such as enabling and disabling modules.  For
configuration changes not handled by the configuration override system,
you can use configuration filters of the Config Filter module.

## Ignoring Development Modules

Use the [Config Split](https://www.drupal.org/project/config_split) module to
split off development configuration in a dedicated config directory.