Power and Ground Planes
From
In the following image of the front of the board, the copper areas highlighted in red compose the +5 volt plane.
In the following image of the back of the board, the copper areas highlighted in red compose the ground plane.
In general, the closer you draw power to where the power and ground enter the board, the better off you will be. That is why the 4 5 Volt and 4 Ground vias are positioned in the location near the edge connector.
