iOS 10.3.2 update is out for the iPhone, iPad, and iPod Touch – bugfixes galore!
A final (or close to final) touch-up of iOS 10 before iOS 11 takes reigniOS 10.3.2 is an update meant to fix bugs while improving performance and security features. You won't see any new functionality added, but given that each of the five (or so) beta versions Apple released prior to the official launch contained thorough lists with fixed bugs and issues. There's a lot this update does behind the scenes, so don't dismiss it as inessential.
As a reminder, iOS 11 is just around the corner, ready for an announcement at Apple's WWDC conference which starts June 5. Some rumors of little credibility but big hope suggest iCloud integration and more contextual learning capabilities for Siri, as well as group FaceTime calls and design tweaks as possible new additions. Apple doesn't seem to be running out of ideas anytime soon!