What is skeleton Model in Creo?
I´m a student at a technical college in austria, worked with Creo 2.0 and 3.0 for around 5 years now.
Bacially, the skeleton model is a help to avoid circular refrences, inside it you draw a, well, rough sketch of what you want to draw. Including all dimensions and so on. Then you can create publicating geometries inside it, and can then copy these geometries into the part you are drawing and use them as refrences.
This way you can pretty much change the dimensions of your entire project just by making some changes in the skeleton model. Also if you do the skeleton model properly, you can avoid errors.
In the images i added, you can see the skeleton of a project i am working on right now compared to the final part. If for example i want to build in a different bearing i can avoid having to change all the dimensions in the 3D model, by simply changing the dimensions of the bearing in the skeleton.
Hope my answer helped