AngularJS is a framework ( client-side ) for web applications that embeds HTML, CSS and Javascript. It basically focuses on:-

1.Coding data access, Reading, form validations - are some functions in which many people are not good at while doing all these simultaneously. AngularJS provides separation between developer and designer. A developer can take HTML/CSS layout and a designer can refactor the layout without interfering into the code.

2.Rendering views from data - Angular provides a brilliant feature of data binding.

a. Injecting views, re-rendering when data changes.

b.There are watchers, listeners to keep a look at the changes and informing about it after the code executes and manipulates (or updates) the model.

3. Divided into fragments - Angular provides separation of concerns that accounts for enhanced testability. It is divided into pieces- controllers, services, views and models. It also provides a set of directives, filters, modules that helps in achieving the right balance of complexity.

4. MVC architecture - Angular MVC structure provides a clean separation of layers. It separates the business logic from its presentation layer by dividing into three components-
a. Model
b. View
c. Controller

(For details in MVC architecture please go to the following link-
http://findnerd.com/account#url=/list/view/MVC-architecture-in-angular/15471/)

5. Deep linking URL - We can send URL to other people and reload any page in browser. We can create SPA’s and provide navigations without page refresh.