Layer Security is where you can control user permissions for this specific layer in this map
Security is where you can control user permissions for this specific layer in this map. The Default section will show a user's inherited permission for this layer based on the map settings, and you can drag the user to the section of the desired permission to change that user's permission for just this layer.
TIP: To see a brief overview, go to the "Layer Security" chapter in the video below.