The file localSettings.php contains code and switches to be used in the client-side application:
debug-mode to switch debugging information on and off
code to switch different forms of logging on and off
the time zone used at run-time
a time limit for running PHP.
productionEnv to switch between development and production mode
database credentials for the application to log into the database
a switch loginEnabled to allow logging into the system
allowedRolesForImporter to specify roles with access to the Excel importer.
run-time parameters for the Exec engine.
run-time parameters for extensions such as OAuth.