The Apple Watch Series 7 comes equipped with an S7 Chip, whilst the Apple Watch SE is equipped with an S5 Chip. As a result, the Series 7 is approximately 20% quicker than the SE.
The Apple Watch Series 7 is equipped with a blood-oxygen sensor and even allows users to do an electrocardiogram on themselves. Wearing an Apple Watch Series 7 is a good idea if monitoring your health is something that interests you.