The form class is an application-specific object that contains both the underlying data hierarchy for the application and the database access required for data procurement in the form of ABAP/4 coding. When creating the data hierarchy, particular emphasis was given to a logical view of the data model. Therefore, the form classes are comparable to logical databases. In contrast to logical databases however, they have the advantage that they can swap two equal levels and duplicate a level in application forms.
Form classes are used by application forms to create forms, that is, correspondence.
A form class consists of a hierarchy representing a logical view of the data model for each application or an application process. The related Form Class Library contains access instructions in the form of ABAP subroutines. Further controlling properties are defined in the Attributes of a form class.
Form classes are a fixed component of an application and cannot be changed or replaced. Form classes are usually independent of the use of the data and particularly of the category of the application form.