Model space can contain one or more viewports.
AutoCAD usually begins a new drawing using a single viewport that fills the entire graphics area. You can split the drawing area to display several viewports simultaneously. For example, if you keep both the full and the detail views visible, you can see the effects of your detail changes on the entire drawing. In each tiled viewport, you can do the following:
You can display tiled viewports in various configurations. How you display the viewports depends on the number and size of the views you need to see.