SpringMVC sending data from controller to view and vice versa

1)Model 

Model will be place in the method parameter. We have to use model.addAttribute(String key, Object value)

@RequestMapping("/home")
public String home(Model model){
    model.addAttribute("name", "Himal");
    model.addAttribute("id", 2225);
    return "home";
}

2)ModelAndView
With model and view, define it inside method. ModelAndView modelAndView = new ModelAndView("pagename");

return modelAndview

@RequestMapping("/help")
public ModelAndView help(){
    ModelAndView modelAndView = new ModelAndView("help");
    String s = "this is help";
    List<String> stringList = new ArrayList<>();
    stringList.add("Me");
    stringList.add("Myself");
    modelAndView.addObject("stringList", stringList);
    modelAndView.addObject("s", s);
    return modelAndView;
}