How can a laravel project work without routes and controllers?

I imported bagisto (an eCommerce laravel project ) from GitHub. i configured it on localhost and it works mostly. I wanna make changes in this project to make my own website . When i look at the source code, i realized the routes and controller files were literally empty. Im wondering, how can a laravel project work without having routes or controllers. There is definitely something i am missing. I'd share the web.php file or controllers but they are empty, If you require to look at any other file, please let me know, ill add it.

via Chebli Mohamed