1. When you start the application , it parses the markups or tags using the compiler.
2. The DOM generated after parsing is the View .
3. <ng-app/> is the directive that initializes the application.
4. The <ng-model/> directive stores/updates the value of the variable.
5. When compiler encounters double curly braces , it replaces with evaluated value
6. {{ expression | filter }} : Here the filter formats the value from expression
7. supports two-way data binding.( when ever input value changes , the output will be changed automatically )
8. <ng-controller/> defines the Controller in MVC pattern.Most of the time its defined in .js file.
9. When the controller is defined with the above tag, it can be accessed inside HTML tags.
Buminda 
nice and simple explanation.. cheers!!