在Laravel中使用另一个模型扩展一个模型

Question

I am pretty new to laravel and currently exploring its concepts. In some videos I saw a concept of models inheritance. I wonder if we can use models relationships in laravel 5.6 then why we need to inherit models. In which case we need to or should inherit models.

eg Base Model:

class User extends Authenticatable
{

}

eg Child Model:

Class UserTypeOne extends User()
{
}

eg Child Model2:

Class UserTypeTwo extends User
{
}

Thanks in advance.