An xwidget is a special display element, such as a web browser, that can be embedded inside a buffer. Each window that displays an xwidget will also have an xwidget view, which on X-Windows corresponds to a single X window used to display the widget.
Neither of these objects are readable; their print syntaxes look like ‘#<xwidget>’ and ‘#<xwidget-view>’, respectively. See Embedded Native Widgets, for a more detailed description of xwidgets.