Angularのファクトリとサービスの違い ref: http://qiita.com/nakana/items/31552f903af728175707

file0.txt

angular
  .module('hoge')
  .factory('hogeFactory', function(){
    function func1 (){}
    function func2 (){}
    function func3 (){}
    return {
      func1: function(){
        return func1();
      },
      func2: function(){
        return func2();
      },
      func3: function(){
        return func3();
      },
    };
  });

file1.txt

function functionName (){}

file2.txt

var functionName = function(){}

file3.txt

angular
  .module('hoge')
  .factory('hogeFactory', function(){
    function func1 (){}
    function func2 (){}
    function func3 (){}
    return {
      func1: func1,
      func2: func2,
      func3: func3,
    };
  });

file4.txt

angular
  .module('hoge')
  .service('hogeService', function(){
    this.func1 = function(){}:
    this.func2 = function(){}:
    this.func3 = function(){}:
  });

file5.txt

function Person(name, age){
  this.name = name;
  this.age = age;
  this.introduce = function(){ console.log(this.name + 'です。' +  this.age + '才です。'); };
  this.jump = function(){ console.log('ぴょーん'); };
  this.eat = function(){ console.log('ぱっくん'); };
}

var taro = new Person('太郎', 10);
taro.introduce();
taro.eat();
taro.jump();

file6.txt

function person(name, age){
  var object = {};
  object.name = name;
  object.age = age;
  object.introduce = function(){ console.log(this.name + 'です。' +  this.age + '才です。'); };
  object.jump = function(){ console.log('ぴょーん'); };
  object.eat = function(){ console.log('ぱっくん'); };
  return object;
}

var taro = person('太郎', 10);
taro.introduce();
taro.eat();
taro.jump();

file7.txt

function person(name, age){
  function introduce(){ console.log(this.name + 'です。' +  this.age + '才です。'); },
  function jump(){ console.log('ぴょーん'); },
  function eat(){ console.log('ぱっくん'); },

  return {
    name: name,
    age: age,
    introduce: introduce,
    jump: jump,
    eat: eat
  };

var taro = person('太郎', 10);
taro.introduce();
taro.eat();
taro.jump();

file8.txt

angular
  .module('hoge')
  .service('hogeService', function(){
    this.func1 = function(){}:
    this.func2 = function(){}:
    this.func3 = function(){}:
  })
  .factory('hogeFactory', function(){
    function func1 (){}
    function func2 (){}
    function func3 (){}
    return {
      func1: func1,
      func2: func2,
      func3: func3,
    };
  })
;