AngularJS: Why people prefer factory to share data between controllers [duplicate] - angularjs

Question

This question already has answers here:
AngularJS: Service vs provider vs factory
(30 answers)
Closed 5 years ago.
i am new in angular. so trying to know how to share data between two controller and search google. i visited few pages and found most of the time people use factory to share data. i just like to know can't we do it by service instead of factory ?
1st example
<div ng-controller="FirstCtrl">
<input type="text" ng-model="data.firstName">
<br>Input is : <strong>{{data.firstName}}</strong>
</div>
<hr>
<div ng-controller="SecondCtrl">
Input should also be here: {{data.firstName}}
</div>
myApp.factory('MyService', function(){
return {
data: {
firstName: '',
lastName: ''
},
update: function(first, last) {
// Improve this method as needed
this.data.firstName = first;
this.data.lastName = last;
}
};
});
// Your controller can use the service's update method
myApp.controller('SecondCtrl', function($scope, MyService){
$scope.data = MyService.data;
$scope.updateData = function(first, last) {
MyService.update(first, last);
}
});
2nd example
var myApp = angular.module('myApp', []);
myApp.factory('Data', function(){
var service = {
FirstName: '',
setFirstName: function(name) {
// this is the trick to sync the data
// so no need for a $watch function
// call this from anywhere when you need to update FirstName
angular.copy(name, service.FirstName);
}
};
return service;
});
// Step 1 Controller
myApp.controller('FirstCtrl', function( $scope, Data ){
});
// Step 2 Controller
myApp.controller('SecondCtrl', function( $scope, Data ){
$scope.FirstName = Data.FirstName;
});
examples are taken from this url Share data between AngularJS controllers
please guide me.

Answer 1

Both .service() and .factory() are both singletons as you’ll only get one instance of each Service regardless of what API created it.
Remember that .service() is just a Constructor, it’s called with new, whereas .factory() is just a function that returns a value.
Using .factory() gives us much more power and flexibility, whereas a .service() is essentially the “end result” of a .factory() call. The .service() gives us the returned value by calling new on the function, which can be limiting, whereas a .factory() is one-step before this compile process as we get to choose which pattern to implement and return.