The option to group hubs is a privilege given us hubbers to make things easy and systematic. It's a scientific system to render things harmoniously so as to avoid clutter. Because of individual differences, we group our hubs according to our individual whims and capricies. We may group them according to categories, such as sports, health and sanitation, crimes and punishment, etc. Be reminded that we don't follow a format from hubpages. Each of us has our own unique and peculiar way of grouping hubs. So expect a yawning difference in the categorization and arrangement of hubs..
After publishing a hub, fail not to visit your group section so as to place the new published hub in its proper group. The new published hub remains in the "orphan" category until it is visited and properly categorized.
There is a big difference in the way we group our hubs on "Group" from the way our hubs are grouped in our "profile". The latter is hubpages' version.
When hubs are group, it systematizes navigation for users and hubbers, Without need of signing out, we can go visit and read other hubs by merely clicking the link located at the hub's ending.