Fields are mainly distinguished between identifiers (Id) and attributes (A). This clarifies the purpose of fields: Id Fields for searching and distinguishing from data records and attributes with the values of the data record.
The Id fields identify data records technically, but this does not mean the technical key field.
Usually the Id fields are arranged first in the table. This then has the following effects:
It is sorted according to the ID fields (from left to right).
Data records are also recognized by the appropriate ID fields in the tables in the data transfer functions.
Visually, Id fields can be displayed with a different color, which can be set in the design template.