On the left side of Figure 1, the magnified portion shows how each group of five holes is interconnected together under the board. This means that each set of five vertical holes are connected together into a row look Figure 2. Each row is individual, and this continues across the board. Note that the upper rows are separated by a gutter from the lower rows. There is no connections between the upper and lower rows you can see that figure2. It shows you how each vertical hole is connected. It also shows you how upper row and lower rows are separated. Across the top and bottom of the board you can see two long rows of holes. Each row of holes is interconnected see figure 2 and there are two individual rows at the top and bottom. These are generally used for power supply or common connections.