The work area is the central space of the interface. It is the artboard on which you will create your mapping shapes.
The Canvas
The black rectangle in the center corresponds to the Canvas. It corresponds to the area that is displayed in your output, which means that anything you draw outside of it won't be rendered in your output window, as shown in the picture above.
The Canvas size is indicated at the top of the work area, and you can configure it from theOutput Setup. Learn how to setup your Canvas properly in "Setting up the Canvas and launching a projection".
Note: the shapes displayed in your work area are always the ones in the currently active sequence (the one that has a yellow title bar).
The View toolbar
At the top of the work area, you'll also find the View toolbar, that contains the following options:
- Shapes info:
the total number of shapes in the currently active sequence, 
the number of shapes in your current selection. - Zoom options:
zoom out, 
zoom out, 
zoom to fit or edit the value precisely in the input field. - Pan options:
move around the work area.
Learn more on how to navigate the work area in "Overview & Navigation".