Group or Parent, what is the difference? When do you use which?
I use parent when I need the pivot pointed to the parent… eg: a car… parent = body, child = doors, bumpers, etc…
Group and Parent are completely different. Parent affects how objects relate to each other in 3D space. If you have a parent-child relationship, then if you rotate, translate or scale the parent the child rotates translates or scales.
Groups have nothing to do with how the objects relate in 3D space. They have a couple of main uses. They can be used to control lighting on objects (you can set lights to only affect objects in certain groups) and they can be used to append multiple objects together in a new .blend file. If you want to import, for example, a rigged mesh in a new .blend file, you can do it most easily by first putting all the related objects into a group and then appending the single group.
Plus you can use vertex parenting, where you parent to a single vert (or triple of verts) and bone parenting where you can parent to a bone. Again, this just makes the child dependent on the parent for its movements in 3D space.
Got it. I will experiment. Tx.