Document the difference between Retroactive updates versus Active updating

Although this is an old post, I came across it having the same question. Since I couldn't find the answer, I did a trial with both options. "Retroactive" will run through all the nodes and update the paths right after saving the content type. "Active updating" will only update the path when the node is saved. So use retroactive if you want to update all paths immediately. Otherwise use "Active updating" for a more manual process where you have to update/save each node.