Auth controls who can use an object on private property.
By default only the owner of a deed is the only one able to do anything on a claimed plot of land. This includes digging and placing blocks.
The owner of the deed can give permission to others to work on the claimed land associated with the deed. This is done by holding a Land Claim Stake and pressing
E on the land, clicking the name of the deed while standing on it, or using a Real Estate Desk.
By default, a crafting station on private property claimed with a Land Claim Stake will only be usable by the property owner. This can be changed in the "Auth" tab of the crafting station. Adding player names, demographics or Everyone to the auth list will allow others to use the crafting station.
Crafting stations that are not on claimed property are usable by anyone, even if they are within a partially claimed room.