Apple released iOS 11.3 on 29 March 2018, the twelfth official update to the iOS 11 operating system that first came out in September of 2017.
The update includes support for Advanced Mobile Location (AML), offering a more accurate location when placing an emergency call in a support country.
The iOS 11.3 update is available on all eligible devices over-the-air in the Settings app. To access the update, go to Settings –> General –> Software Update. Eligible devices include the iPhone 5s and later, the iPad mini 2 and later, the iPad Air and later, and the 6th-generation iPod touch.
Read the full article on the iOS update here