This example demonstrates the use of the PDF Portfolio feature (sometimes called Portable Collections). A PDF Portfolio can contain multiple files integrated into a single PDF.
Files in a PDF Portfolio can be in a wide range of file types created in different applications. For example, a PDF Portfolio can include text documents, e-mail messages, spreadsheets, CAD drawings, and PowerPoint presentations. Files added to a PDF Portfolio are not converted to PDF, and you can edit or modify them in their native application without removing them from the Portfolio.
PDF Portfolios offer several advantages over merging multiple files into a single PDF. For more information, see Adobe's Overview of PDF Portfolios.