It's a Domain which has a finite number of values.
Each value has a Code, a Name and a Value.
Code: Credit, Name: Credit, Value: 0
Code: Debit, Name: Debit, Value: 1
If an Attribute or Variable is based on an Enumerated Domain, it will be presented in the Form as a combo box.
It's a good practice to use an enumerator instead of using the value, as shown:
&Var = 1 //BAD
&Var = Type.Debit //GOOD