As we all know AJAX call is used to process an asynchronous request initiated by the browser. The result of AJAX call is not a page transition directly but the action takes place. You can submit forms and datas on a page through AJAX but the page will not refresh as it does in a traditional HTML form submission. In Angular.js we are making an AJAX call to create a service that returns a promise to the returned data, and call that in your controller and handle the promise to load your $scope property. An example is shown below for understanding it better.

The service:

module.factory('myService',function($http) {
   return {
        getFoos:function() {
            //return the promise directly.
             return $http.get('/foos')
                    .then(function(result) {
                     //resolve the promise as the data
                    return result.data;
                    });
        }
   }
});

The controller:

The promise’s then method is handled and get the data. Then sets the $scope property and do what you need.

module.controller('MyCtrl',function($scope, myService) {
   myService.getFoos().then(function(foos) {
        $scope.foos = foos;
    });
});