Apple Watch, what's new, what has changed, do you need a new model?

Now we will compare what characteristics have changed on the new watch, we will also compare it with the old and new
Characteristics	Apple Watch Series 8	Apple Watch Series 7	Apple Watch Series 6
Watch case	41mm or 45mm case		40mm or 44mm case
CPU	S8 SiP with 64-bit dual-core processor; W3 wireless chip; U1 chip (Ultra Wideband)	S7 SiP with 64-bit dual-core processor; W3 wireless chip; U1 chip (Ultra Wideband)	S6 SiP with 64-bit dual-core processor; W3 wireless chip; U1 chip (Ultra Wideband)
Health widgets	Temperature sensor,1 blood oxygen sensor; 12 electrical heart sensor and third-generation optical heart sensor	Blood oxygen sensor; 12 electrical heart sensor and third-generation optical heart sensor
Rhythm notification	High and low heart rate notifications, irregular rhythm notification, and ECG app13
Rescue or assistance system	International emergency calling, 16 Emergency SOS, 2 Crash Detection, 2 and Fall Detection	International emergency calling, 16 Emergency SOS, 2 and Fall Detection
Water resistant	Water resistant 50 meters
Dust resistant	Yes	No
Fast time charge	Yes		No
Network and bluetooth support	LTE and UMTS, Wi-Fi, and Bluetooth 5.3	LTE and UMTS, Wi-Fi, and Bluetooth 5.0
Other	GPS/GNSS, compass, and always-on altimeter
Built-in speaker and mic	Yes

Sum up

The shape of the case has changed only in Series 8, in Series 7 and Series 6 it's same.
with each generation, the processor became more powerful.

Currently the most powerful and slightly power-consuming processor is the Series 8 version, although on the other hand it is very similar to previous versions of the processor.

The saving or alert system has also been updated, but is still very similar to the previous system
Water resistance is present in all 3 watches, but dust resistance is only in the newest version
Gps is also present in all 3 models
The microphone is present and functions very well

More information about the new watch on the official website on this link

If you are a lucky owner of a Series 7 watch, then my opinion is that it’s better not to update, but you really need it or want it, then it’s better to take it

Well, if you are the owner of Series 6, then you should think about updating