How do I see how many Mac OS?

1. Click on the top left corner of the toolbar (Apple logo) logo, about this machine--more information--system report--(in the left sidebar) software (some computers are not for example the first picture )

2. Enter Command uname-a carriage return

X86_64 indicates that the system is 64-bit

The i686 represents the system 32-bit

3. Ioreg-l-P Iodevicetree | grep "Firmware-abi" | Sed-e ' s/[^0-9a-z]//g '

EFI64-64-bit
EFI32-32-bit

How do I see how many Mac OS?