Series 7 is now 41 mm and 45 mm in size with 33 percent faster charging than series 6.
Display size is increased and offers 1000 nits of brightness. Everything inside the new display is big now with smaller bezels
Not a big change in battery life but the charging is going to be significantly faster on the apple watch series 7
The charging cable is now USB C instead of USB A. It charges 33% faster as compared to series 6.
Front display is crack resistant and 50% thicker which adds strength and durability to the Apple watch series 7
Every sensor has been improved and performs better. The sensors are now protected with IP6x dust resistant technology
The Apple Watch Series 7 display has 2 new watch faces: Contour and Modular Duo.