config
The config directory, contains all of your application's configuration files.
config/env.php
contains all the main Boostack configurations and is automatically generated by the setup procedure.
By default it is ignored by git because it contains the configurations of a specific environment (for example: development, staging or production).
config/global.env.php
global.env.php contains configurations shared by all possible environments, regardless of whether they are development, staging, or production.