what does namespace app\controllers do ?

Yii 2.0 General Discussions
1

I dont understand why controllers need namespace such as "namespace frontend\controllers"

When I remove "namespace", I got




Unknown Class – yii\base\UnknownClassException


Unable to find 'frontend\controllers\CountryController' in file:

 C:\Program Files (x86)\www\erp/frontend/controllers/CountryController.php.

 Namespace missing?
2

you should read this.ref link