hi Monica. Shiralkar,
No its not necessary that every time
you should return ModelAndView object. you can also return Map or List.
and
string(which will be accounted as view name).
Suppose you are doing Ajax call to controller and you want list of objects returned from controller than you need to put @RequestMapping annotation(if you are using Spring MVC 3.0 or above) before controller method name that you want to call.
thanks
Prashant