The mesh system in Blender is very powerful and flexible, in fact, so flexible that you might just break your model.
Thankfully it’s quite simple once you understand the sorts of problems you can get in and how to get out of them.
In Maya for example if you were to try to delete all the faces of an object, you’ll still be left with a triangle. So 1 face, 3 edges, 3 vertices. If you try to delete that, Maya will ignore you. You won’t even be able to haggle it down to just an edge and certainly not a single vertex.
In Blender, no such restrictions exist.
Check out this quick ‘Mesh System’ segment of the following video…
It starts at 12 minutes 16 seconds.
Hope someone finds it of interest/use.