Every resource (i.e. reducer, tframe, predictive model, etc.) has three level of permissions that can be assigned to a user.
Read: allows the users with read access to view the resource and read all the data that it contains
Write: allows users with write access to edit the resource and assign new permissions to it
Execute: allows users with execute access to run the resource (i.e. running a reducer)
Setting a resource to public will grant everyone read and execute access to it.
Access levels can be assigned to users by clicking on the lock icon on the top right hand menu of every resource.