AEM Forms, or XFA (XML Forms Architecture), is currently the most flexible and powerful tool for creating interactive documents. AEM Forms are not, in fact, PDF documents—they are XML files wrapped in a PDF container. This feature creates some Accessibility and compatibility issues with major web browsers and some other software.
The main advantage of this architecture is that the Developer can control all document objects and their properties.

Example: Scaling an XFA document in AEM Forms Designer to compliance with Accessibility requirements