# Development - Application Modes

There are several modes by which your can run your application.

- production - used when application uploaded to external use
- debug - normally used in development process
- demo - used to show features of application without possibility to change important things in database
- test - used for testing purposes
- hidden - used to cases when framework must run in background without output into browser

The mode for each application must be defined in `index.php` file.

    // production | debug | demo | test | hidden
    defined('APPHP_MODE') or define('APPHP_MODE', 'debug');

You may find more information abount index dispatcher file here.