There is a strong relationship between authority and interest in SpatialOS. See the concepts documentation on authority and interest for an overview of this topic.
Worker instances are responsible for the computation associated with entity components in a SpatialOS world. To do this computation, they make updates to and receive updates from the entity database in the Runtime.
To ensure that only one worker instance at a time sends updates to the entity database about an entity component, SpatialOS has the concept of write access authority.
You set up which worker types can have write access authority as part of your SpatialOS project’s configuration. Which worker instance has write access authority during runtime depends on how you set up your load balancing configuration.
Find out more about write access authority.
Because worker instances might need to know the status of entity components that they don’t have write access authority over, they can have interest in those entity components.
A worker instance with interest in an entity component can receive updates about that component, but it needs specific circumstances to have active read access and actually receive those updates. You set up those circumstances when you configure your SpatialOS project.
Find out more about active read access and the two types of interest in SpatialOS.