A PDF document that contains interactive forms can be thought of as having a form data layer superimposed on the primitive graphics layer. While a PDF file contains both layers, a Forms Data Format (FDF) file contains only the data layer. An FDF file is smaller and simpler than a PDF file, and can be imported into a PDF file that has a form structure that corresponds to the form in the FDF file.
After a user has edited a form in a PDF file that has been created from an SPS, they can do the following:
These actions, and also how to design fillable PDF forms so that the user can submit form data to a server, are described in the sub-sections of this section.