Lets say continue with User example (you may have controller with store method and update method). To use FormRequests you use type-hinting the specific request.
...
public function store(App\Http\Requests\StoreRequest $request, App\User $user) {
//by type-hinting the request class, Laravel "runs" StoreRequest
//before actual method store is hit
//logic that handles storing new user
//(both email and password has to be in $fillable property of User model
$user->create($request->only(['email', 'password']));
return redirect()->back();
}
...
public function update(App\Http\Requests\UpdateRequest $request, App\User $users, $id) {
//by type-hinting the request class, Laravel "runs" UpdateRequest
//before actual method update is hit
//logic that handles updating a user
//(both email and password has to be in $fillable property of User model
$user = $users->findOrFail($id);
$user->update($request->only(['password']));
return redirect()->back();
}