Hierarchical Cluster View

Hi all, 

I am using the 'Hierarchical Cluster View' node. I do not quite understand what the Distance View is displaying. What exactly is plotted on the y axis?

Thanks in advance

This is the distance between the items on the x axis. 1 being totally different and 0 being the exact same. From the prior nodes to the cluster view, the distance on the y axis is defined as either the average, max, or min distance between items within the cluster.

Thanks a lot!