I read somewhere that there are many subsystems in windows(any version) like win32 subsystem POSIX subsystem etc.To support all of these potential subsystems, Microsoft made unified set of APIs which are called wrappers of each subsystem. In short, all subsystems have all the needed libraries for them to work. For example Win32 apps call the Win32 Subsystem APIs, which in fact call NT APIs (native APIs, or just natives). Natives don't require any subsystem to run.

Now since natives don't require any subsystem to run are they same as interrupts or do they use interrupts.And what are system calls.Please differentiate between the terms syscalls, interrupts, native api and dll wrappers.
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The native API has a set of DLL functions just like the win32 API, which in turn end up either issuing the syscall interrupt, or using the syscall instruction (on recent processors, and XP and newer OS).

Not much advantage of using the native API, except when some features aren't exposed to the win32 API.