Customize environment-specific configuration using env.php in Magento

Magento uses the env.php file to store environment-specific configuration values that aren’t shared from environment to environment. Unlike config.xml files, which contain default module config settings, the env.php file holds potentially sensitive configuration that varies between environments.

Here's what a typical env.php file looks like:

return [
    'backend' => [
        'frontName' => 'admin'
    ],
    'db' => [
        'connection' => [
            'default' => [
                'host' => 'localhost',
                'dbname' => 'magento',...