AngularJS is a JavaScript Framework which is developed by Google.

 Some basic concepts :
1. The main benefit of angularJS is (I Think) we can declare variable in html part.
2. Declared variable should be within two curly braces.

 Some basic concepts for this example :
1. To run AngularJS we have to add "ng-app" attribute to the <html> tag.
2. Add below AngularJS reference into <head> tag:
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>

 3. Add ng-model for any input field.

 Hello World :

 <html ng-app>
        <head>
               <title>Hello World</title>
               <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>
       </head>
       <body>
               <input type="text" ng-model="someVariable"/>
               <p>{{someVariable}}</p>
       </body>
</html>


Output :
If we run this code then we can see an input tag.
Whatever we write in this tag we can see that text in <p> tag.