The Display

Probably the biggest new feature of the Series 5 Apple Watch is that the display will always stay on — something that a lot of people have been clamouring for since the wearable first debuted four years ago.
The lack of an always-on display was obviously a concession to battery life, and Apple traditionally handled it pretty well — you don’t need to see your Apple Watch unless you’re actually looking at it, and the accelerometer and gyroscope allowed the device to (usually) light up when you raised your wrist. It was a reasonable trade off for normal daytime use, although when Apple later debuted Nightstand mode, we found ourselves wishing that the Apple Watch would at least stay on to show our clock on our nightstand, since it was running on power at that point anyway.
Now, Apple has managed to figure out a way to keep the display on all the time, without sacrificing battery life. This is as a result of new display technology — a “low-temperature polysilicon oxide display” — and new sensors for things like ambient light and other power management chips. Despite all of this, however, the resolution and brightness of the display remains unchanged.
It seems like a small thing, but it’s going to be a marquee feature for a lot of users; if an always-on Apple Watch is something you’ve always wanted, this feature alone could make the Series 5 a must-buy.