natural key
type of unique key in a database formed of attributes that exist and are used in the external world outside the database
en-GB/ˈnæt͡ʃəɹəl ˈkiː/
en-US/ˈnæt͡ʃɚəl ˈki/
type of unique key in a database formed of attributes that exist and are used in the external world outside the database