Drupal Site Settings : Using settings.php

Drupal settings file can contains variable which can use to use for different configuration in different environments.

Example:
env_name
default_info_nid

$settings['env_name'] = 'Local';
$settings['default_info_nid'] = 1';

Read the settings

use Drupal\Core\Site\Settings;

$envName = Settings::get('env_name');
$nid = Settings::get('default_info_nid');