xcode instrument vm tracker

Why does iOS have swap memory size? According to my understanding, iOS only has memory compression, not swapping, what does swapping mean here? One more question, does memory compression only compress dirty memory? My understanding is that for dirty memory, it is compressed, and for clean memory, it is directly page out to the outside.

yeah, "swap" in instruments is actually your compressed memory in iOS. see https://developer.apple.com/videos/play/wwdc2018/416/?time=125

xcode instrument vm tracker
 
 
Q