What is a Spatial Anchor?

https://aka.ms/WhatIsAnchors

Spatial Anchors allow you to place virtual object in a specific point in your real world. You can think of them as more accurate GPS that works indoors as well as outdoors. Spatial Anchors are available for iOS, Android mobile devices and HoloLens headsets. Azure Spatial Anchors gives you a way to save and share anchor points, so that you can share the virtual objects or information between multiple devices and persist them over time.

Azure Spatial Anchors allow you to display data in the right context.