Services are javascript functions and are responsible to do a specific tasks. This makes them an individual entity which is maintainable and testable. Controllers, filters can call them as on requirement basis. AngularJS provides many inbuilt services like, $https:, $route, $window, $location etc. Inbuilt services are always prefixed with $ symbol.

$location service

The $location service has methods which return information about the location of the current web page.

Example: Display the page URL.

<h3>{{myUrl}}</h3>

<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope, $location) {
    $scope.myUrl = $location.absUrl();
});
</script>

The $http Service

The $http service is one of the most common used services in AngularJS applications. The service makes a request to the server, and lets your application handle the response.

<h1>{{text}}</h1>

<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope, $http) {
  $http.get("file.html").then(function (response) {
      $scope.text = response.data;
  });
});
</script>

The $timeout Service

Example: Display a new message after two seconds.

<h1>{{myHeader}}</h1>

<script>var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope, $timeout) {
    $scope.myMessage = "Hello World!";
    $timeout(function () {
        $scope.myMessage = "How are you today?";
    }, 2000);
})</script>;

The $interval Service

Display the time every second

<h1>{{theTime}}</h1>

<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope, $interval) {
  $scope.theTime = new Date().toLocaleTimeString();
  $interval(function () {
      $scope.theTime = new Date().toLocaleTimeString();
  }, 1000);
});
</script>