Access control - "user role" - Definition and exemple

Ok thank you,

Can we configure it for certain users with roles or for the overview, locations, devices and properties, this is only possible by doing Settings → API Security → Enable/Disable implicit user role?

And I don’t know why but when I disable the API implicit user role, I’m using temperature and the temperature of my item will disappear like that:

And when I enable it again it displays that (as before):