$document is an Angular service which reference to the browser's window.document object.
<script>
var app = angular.module('documentExample', []);
app.controller('ExampleController', ['$scope', '$document', function ($scope,
$document) {
$scope.title = $document[0].title;
$scope.windowTitle = angular.element(window.document)[0].title;
}]);
</script>
<div ng-app="documentExample" ng-controller="ExampleController">
<p>$document title: <b ng-bind="title"></b></p>
<p>window.document title: <b ng-bind="windowTitle"></b></p>
</div>
