Modos de funcionamiento de un lector de pantallas

En How Windows Screen Readers Work on the Web se explican los diferentes modos de funcionamiento de un lector de pantallas:

• Document mode: The most common mode used to access web pages using Windows screen readers will be referred to here as “document” mode. This is also often called “virtual” or “browse” mode, used as proprietary terminology by specific screen readers. This is the default mode that is invoked when a page loads in the browser. This mode may be overridden by web pages who auto focus a form field or apply certain WAI-ARIA roles.
• Application mode: When users need to interact with web pages such as entering text into a form field, document mode must be disabled and the screen reader must be switched into “application mode.” This mode also goes by the proprietary screen reader terms of “Forms” and “Focus” mode. Application mode is necessary to interact with forms, dialogs and web applications. In application mode, all of the keystrokes which would normally manipulate the invisible document cursor are instead passed through to the web page. This allows a user to enter text into a form field or use the arrow keys to traverse the options in a drop-down. Application mode is usually invoked by placing focus on a form field and pressing a keystroke such as the Enter key. Some screen readers will automatically switch into application mode when a form field is encountered. Application mode can also be invoked by web page authors through the application of certain WAI-ARIA roles such as role="dialog" or role="application" to page elements.