Check [this YouTube video](https://www.youtube.com/watch?v=TqMXzEK0nsA) for explanation


## 135 packages by Yii

The Yii team split the functionalities if Yii3 into 135 packages which you should check in advance to know what is available. Theiry are listed [here](https://www.yiiframework.com/status/3.0) or the same is also [here](https://www.yiiframework.com/doc/api/3.0). For example [log in](https://github.com/yiisoft/user) and [RBAC](https://github.com/yiisoft/rbac), which can be stored in [DB](https://github.com/yiisoft/rbac-db) or in [PHP files](https://github.com/yiisoft/rbac-php/). And many more like "active-record" (which is now finished), "form-model" or "boostrap5".

## invoke()
The `__invoke()` public method is called when you call the **instance** as a method. (Therefore the constructor was already executed)

```php