It’s worth noting值得注意的是

 It’s worth noting that in JavaScript applications the Model is often connected via Ajax to a back-end service acting as a database for stored data represented there.

值得注意的是，在JavaScript应用程序中，模型通常是通过Ajax连接至一个作为的数据库（用作保存系统所表示的数据）的后台服务器。