What characterizes a Single Document Interface (SDI)?

A Single Document Interface (SDI) is characterized by each window being separate and containing its own menu and toolbar. This means that for every document or file a user opens, a new window is created specifically for that document. Each of these windows operates independently, allowing users to work on multiple documents simultaneously without any shared interfaces or features.

This design choice provides a clear and straightforward user experience, as everything related to a specific document is contained within its individual window. It allows for distinct menus and toolbars that are specific to the task or document at hand, which can be particularly useful in applications where different documents may require different tools or options.

In contrast, other types of interfaces, like a Multiple Document Interface (MDI), would allow multiple documents to be opened within a single main window, sharing the same menus and toolbars, which does not align with the characteristics of SDI. The other options presented do not accurately describe the nature of an SDI, reinforcing the understanding that in an SDI model, independence and uniqueness of each document window are key attributes.