Magento 2.1.18 is the final 2.1.x release. After June 2019, Magento 2.1.x will no longer receive security patches, quality fixes, or documentation updates.To maintain your site's performance, security, and PCI compliance, upgrade to the latest version of Magento.
Magento configuration files
Magento provides configuration files that enable you to easily customize a component. We also enable you to create new configuration types to extend default functionality.
