AxInternalBase Class

The AxBC table classes have the following characteristics:

• A One-to-one relationship between class and table.
• The classes use the same name, with an Ax prefix, as the corresponding table. For example, the AxSalesTable class changes records in the SalesTable table.
• The interface methods on the AxBC table class for fields in the related table use the same name, with a prefix of parm, as the fields on the table.For example, the parmCustAccount method on the AxSalesTable class is used externally to set or get the value of the CustAccount field in the SalesTable table.
• The classes change the table records directly by setting the values of the table field and executing the update and insert methods on the table.
• The default business logic is performed in the methods the methods that have a prefix of set. For example the setCurrencyCode method on the AxSalesTable class is used internally to set the value of the CurrencyCode field in the SalesTable table, depending on the value in the CustAccount field.

http://msdn.microsoft.com/en-us/library/axinternalbase.aspx