The context where one or more user stories takes place:
Each context location has an image -- which helps create a more helpful and visually rich context map. This can be a design screen-shot, a wireframe, or any other visual aid.
On the canvas map, links can be dragged from several hot-spots on the edge of each location to connect it to other locations. This flexibility allows you to show both inter-linking network-style flow structures and hierarchical relationships.
From the story form, you can select any number of "Canvas Contexts" from those which have been added to the map
From the context/location detail page you can add stories that automatically associate with a user.
Seeing at a glance stories that happen in a context is a quick way to ramp up a team's contextual understanding -- which leads to more efficient collaboration and less missed connections.
Even on digital projects, "screens" may not always work for "behind the scenes" stories. For these stories, you can create canvas locations using other concepts like code modules or execution environments (servers, cloud systems), keeping in mind the principle that this is in some sense "where the action occurs."