Service Factory
Creates a service object in Angular by using the "new" keyword. In Angular, factories are the most popular way to create and configure a service.
It does not use a type-friendly injection mode. It uses a type-friendly injection mode.
It cannot create primitives. Factory can be used to build primitives.
It is configurable. It is not configurable.
BY Best Interview Question ON 19 Jun 2020

Example

Example of a Factory in Angular

app.controller('myFactoryCtrl', function ($scope, myFactory) {
  $scope.artist = myFactory.getArtist()
})

app.factory('myFactory', function () {
  var _artist = '';
  var service = {}

  service.getArtist = function () {
    return _artist
  }

  return service;
})

Example of a Service in Angular

app.controller('myServiceCtrl', function ($scope, myService) {
  $scope.artist = myService.getArtist();
});

app.service('myService', function () {
  var _artist = '';
  this.getArtist = function () {
    return _artist;
  }
});