Factory vs Service

angularjs factory vs service do the same thing, just a different way of instantiation

HTML

<script src="http://code.angularjs.org/angular-1.0.0rc9.js"></script>
<div ng-controller="HelloCtrl">
    <p>{{fromService1}}</p>
</div>
<br />
<div ng-controller="GoodbyeCtrl">
    <p>{{fromService2}}</p>
</div>

JavaScript

//angular.js example for factory vs service
var app = angular.module('myApp', ['module1', 'module2']);

var service1module = angular.module('module1', []);

service1module.factory('module1.myService', function() {
    return {
        sayHello: function(text) {
            return "Service1 says \"Hello " + text + "\"";
        }
    };
});

var service2module = angular.module('module2', []);

service2module.factory('module2.myService', function() {
    return {
        sayGoodbye: function(text) {
            return "Service2 says \"Goodbye " + text + "\"";
        }
    };
});

app.controller('HelloCtrl', ['$scope', 'module1.myService', function($scope, myService) {
    $scope.fromService1 = module2.myS.sayHello("World");
}]);

app.controller('GoodbyeCtrl', ['$scope', 'module2.myService', function($scope, myService) {
    $scope.fromService2 = myService.sayGoodbye("World");
}]);