The "skeleton" consists of a number of individual named joints linked together in a chain. The Vue user can see the parts of the skeleton in the Objects window to the lower right. You may have to click on each part of a skeleton to expand it completely.

Hopefully, the model-builder has given each of the joints a good set of names so that you can guess where they fit in the model, and what function they might serve.

If the model-builder is using professional 3d modelling conventions (non-Poser), the beginning part of the skeleton will move the entire model (or will rotate it), and there will be pieces at the end of each major joint chain that don't really do anything but signify the end.