ps aux displays the list, but where does it get it from - kernel itself or launchd?
ps command enumerates the mach kernel process listing in a similar manner to how many linux (which don't use mach kernel) expose this as the /proc filesystem.
macOS and tvOS and iOS and watchOS all share the same underlying core OS:
- Getting a list of currently running processes
- iOS: Where is /proc/?
- Getting list of pids and process names
- Process list with name and VPRVT
If you want to see the source code - check out xnu section at https://opensource.apple.com/source/xnu/xnu-4570.41.2/