In css:
As we all know that CSS is static and we can only use it to make up our wedsite, while under the AngularJS, it becomes dynamic so that the function of it increases a lot. For example, helping users to notice the input box and reminding which stage they are can be achieved by static CSS.
In ng-model:
It likes an index of the input content, which we can refer to in other places.
Confirmation mechanism:
The main idea of our website, I think, is to communicate with users. Therefore, making sure that all the information we got is valid and safe( to avoid the SQL injection) is a critical design, while, the AngularJS should a good choice. The built-in functions in AngularJS are quite useful. Like $error.email, $valid, $dirty ...
Overall, the AngularJS is a perfect framework of javascript. What it has done comes from javascript, thus, to make js much easier, I deserve AngularJS.