It is covered in the Jetstream docs...
Laravel Jetstream's architecture is a little different from other Laravel application starter kits such as Laravel Breeze
In contrast to Laravel Breeze, Laravel Jetstream does not publish controllers or routes to your application. Instead, Jetstream's functionality is customized via "Action" classes. During the Jetstream installation process, actions are published to your application's app/Actions directory.
...and Laravel Breeze docs
Laravel Breeze is a minimal, simple implementation of all of Laravel's authentication features, including login, registration, password reset, email verification, and password confirmation. In addition, Breeze includes a simple "profile" page where the user may update their name, email address, and password.
Laravel Breeze's default view layer is made up of simple Blade templates styled with Tailwind CSS. Additionally, Breeze provides scaffolding options based on Livewire or Inertia, with the choice of using Vue or React for the Inertia-based scaffolding.