Specify the initial view of the map to display when the map is opened in the Viewer. Users can zoom out from this initial view to see more of the map. When you reference the map in a web layout, you can override this initial view. The unit of measurement varies depending on the selected coordinate system.
To define the initial view manually
The left value should be less than the right and the bottom value should be less than the top.
To avoid map distortion, make sure the numbers fit the current range of the coordinate system.
To set the initial view using the current map view
The current view is used for the initial view of the new map.