title: What are the DAO, DTO and Service layers in Spring Framework?
body: <p>I am writing RESTful services using spring and hibernate. I read many resource in internet, but they did not clarify my doubts. Please explain me in details what are <em>DAO</em>, <em>DTO</em> and <em>Service</em> layers in spring framework? And why usage of these layers is required in spring to develop RESTfull API services.</p>