Android Oreo comes with numerous enhancements over Android Nougat, such as faster booting, new Settings and Quick-Settings UI, Picture in Picture (PIP), Adaptive icons, Autofill, Notification timeout, Samsung has add several new features to the latest software update.
The Android 8.0 Oreo update for the Samsung Smartphones comes with latest Samsung Experience 9.0 with new design and enhancements.
The Oreo update for the Galaxy S8 weighs in at around 487MB and comes with the latest February 2018 security patch. The update is already rolling out to the users of Galaxy S8 users in phases. If you did not receive the update wait for few days or try checking for it manually by heading over to system updates section in the Settings app. Make sure you've at least 50 percent juice left on your phone before updating it.