Hello, open the settings, and then click "Display and brightness" and "light color". I hope my answer is helpful to you.

1, case difference: Apple Watch 7 is equipped with 4 1 mm or 45 mm case, and the screen area is increased by more than 50%; Apple Watch se is equipped with a 40 mm or 44 mm case, and the screen area has increased by more than 30%.

2. Chip difference: Apple Watch 7 is equipped with S7 SiP chip with 64-bit dual-core processor +W3 wireless chip +U 1 chip (ultra-wideband technology). Apple Watch se is equipped with S5 SiP chip with 64-bit dual-core processor and W3 wireless chip.

3, blood oxygen function difference: Apple Watch 7 supports blood oxygen sensor+electrode heart rate sensor+third generation optical heart rate sensor; Apple Watch se supports the second generation optical heart rate sensor.

4, dustproof function: Apple Watch 7 added IP6X dustproof.