With the help of suitable example, describe the development of single document and multi-document interface.

In an Single document Interface (SDI) application, each form runs  in its own application window, and this windows is usually shown in the windows taskbar. Then you can click on the buttons in the taskbar to switch between the open forms. When you use this interface each form can have its own menus and toolbars. In addition, a main form called a startup form typically provides access to the other forms of the application. In this figure, for example, the startup form includes button that the user can click  on to display the other forms.

            The second version of this application uses a multiple-document interface or MDI. In an MDI application, a container form called a parent form contains one or more child forms. Then, the menus and toolbars on the parent form contain the commands that let you open and view forms, and you can use its window menu to switch  between the open forms. When you close the parent form of an MDI application , all of the child forms are closed and the application ends.

            The main advantage of Multi-document interface is that the parent form manages multiple instances of child forms for you. In contrast, if you create multiple instances of a form in an SDI application, you have to manage them yourself. As you can imagine, that can get unwieldy.