A field containing currency amounts

A field containing currency amounts (data type CURR) must be assigned to a reference table and a reference field. Explain

As a reference table, a system table containing all the valid currencies is assigned or any other table which contains a field with the currency key format. This field is called as reference field. The assignment of the field containing currency amounts to the reference field is made at runtime. The value in the reference field determines the currency of the amount.