求教大佬,Model的addAttribute方法为什么能将数据放到页面上去

Question

之前同事给解释了几句,但是没听懂,说是涉及四大域,跪求大佬说下

@RequestMapping("toUpdate")

public String toUpdate(Integer id,Model model) {

List<Door> list = doorService.SelectAll();

model.addAttribute("doorList",list);

Order order = orderService.SelectOne(id);

model.addAttribute("order",order);

return "orderUpdate";