'Series 0' isn't an official term that's ever been used by Apple, it's just become common language when referring to the original 'Apple Watch' since the follow

'Series 0' isn't an official term that's ever been used by Apple, it's just become common language when referring to the original 'Apple Watch' since the follow-ups were called Series 1 and Series 2. Series 1 was the orignal Apple Watch with a better processor and a price cut. Series 2 debuted a the same time and added more features like water resistance and a brighter screen.