In AngularJS, To bind application data to html expressions are used. It is written inside of double braces like {{expression}}. It uses same way as ng-bind.
Following example will show all the expressions of AngularJS:
<html>
<title>My AngularJS Expressions</title>
<body>
<h1>AngularJS Expressions</h1>
<div ng-app="" ng-init="quantity=2;cost=10; colleague={firstname:'Tim',lastname:'Ererld',salary:25000};Points=[10,20,30,40,50]">
<p>Welcome {{colleague.firstname + " " + colleague.lastname}}!</p>
<p>Price(Rs) : {{quantity * cost}}</p>
<p>Salary: {{colleague.salary}}</p>
<p>Points: {{Points[3]}}</p>
</div>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
</body>
</html>