I'll take a stab at it, but there may be errors or some debate here. I think to be more precise, there are basically two categories that people consider "crackery" and the forum headings really don't distinguish two types, thus the confusion.
Sheeted or Laminated Crust - Commercial examples include: Round Table, Shakey's, Straw Hat, etc. The dough is sheeted, folded, repeated then cut with a die cutter. Layering results in structural dough changes and trapped moisture which make the dough puff up. The crust typically has a crispy bottom, some separated layers (voids) then a softer uniform layer just under the sauce. Typically cooked on a deck with baking paper or a perforated disk on a conveyor.
Undeveloped super thin crust - Commercial examples include ? The dough is purposefully undermixed, undeveloped and NOT sheeted. Dough is rolled out typcally by hand with a rolling pin, may or may not be die cut. Some variations include par-baking the crust prior to dressing. The crust is crispy throughout, with virtually no soft layers. Typically cooked in a cutter pan or on a deck.