preface- i'm sequential, and i'm staying sequential

so regarding the "boost settings" screen of the PFC

what does pri/sec mean? primary/secondary turbo? where is the prespool adjustment?

also, what about the duty cycles, is that percent open or percent closed, and if i set mine to let's say 10psi, (.70), does it learn how to keep it at .70? does it change/update the duty cycles?

someone explain this to me in great detail