what is php artisan

Artisan::command('build {project}', function ($project) {
    $this->info("Building {$project}!");
})->describe('Build the project');

use App\Models\User;
use App\Support\DripEmailer;

Artisan::command('email:send {user}', function (DripEmailer $drip, $user) {
    $drip->send(User::find($user));
});