How can I differentiate authentications in laravel? Example: Administrator and Common User without using multauth

You can do this through Middleware .

You can create middleware to check if the current user is of a certain level. So you can have this middleware defined on the routes you are defining and that you want only the administrator to access.

For example, you should first create a middleware .

Run the command php artisan make:middleware AdminCheck .

It will create a file in app/Http/Middlewares/AdminCheck.php . Then edit it, as in the case below:

class AdminCheck
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
        if ($request->user()->admin == false) {
            return abort(403, "Acesso não autorizado");
        }

        return $next($request);
    }
}

Next, you should add this middleware to Http/Kernel of your application:

protected $routeMiddleware = [
    // outros middlewares
     'auth.admin' => App\Http\Middleware\AdminCheck::class
];

Next in your routes, you define a group of routes that can be accessed only by this group:

Route::group(['middleware' => ['auth', 'auth.admin'], function () {
      // Minhas rotas da administração aqui
});

Notes

In the $request->user()->admin == false excerpt I'm doing a check to see if this user was registered in my database as an administrator. In case, it is not necessary that you do the same I did, but it is important you have a way to differentiate an ordinary user from an admin user. This way you will have to work out. I am commenting on this because in your question you cite that you are registered "admin and common user, both in the User table, with the same attributes."