A form is a data structure that describes an area (position and size) of an image, the preprocessing actions to perform on the area and the description of one or more fields or segments. FormFix can manage multiple forms concurrently through the IdentificationProcessor object.

A field is a data structure that describes an area (position and size), the preprocessing actions to perform on the area as well as the type of analysis to perform on it (OCR, OMR, ICR, Mark box, Image or Barcode as set by FieldType). Fields are referred to by either name or index. When a field is created (by AddFormField) it is added to the current form. Only one field is addressed at a time; it is considered the current field and the current field can be changed by SelectFormField or SelectFormFieldIndex.

A form set is a collection of zero or more forms. The FormFix component will have explicit support for form sets in order to support identification of a form within the set. 

Each form must include at least one field. A form typically contains many fields and they can be of different types.

A form may be defined programmatically by specifying the fields, their positions and attributes in the application code. The data that constitutes a form may then be saved to disk as a Form Definition Language (FDL) file which are then parsed by the FormDirector component.