Long and short - long graduation hair is longer in length with shorter layers falling on top, short graduation sorter in the nape at the hair line getting longer as you go up.
All depends on the cutting angle, to cut in orange segments and cut at a 180 will mean the hair at the crown area will be far shorter as you use your perimeter line as your guide.
It really depends on what the Client wants, hair texture and density.
If some one has real fine hair I opulent advise shorter layer and could opt for a 45-90 degree angle starting. I'd work up o the occipital bone at a one length to create. Nice full looking base line and the introduce the layers, so you still have full looking ends and one nice layers in their to create movement.
For thick hair you can start your layers lower down as the base line will look fuller faster and the work on a 180 degree angle pulling the hair straight up creating shorter lighter layer on top flowing nicely down.
Hard to explain!!! Thats how we where taught.
It's more your angles combined with the client on how to create the overall finish.