History of PDF File Types. A PDF file is a Learn about PDF (Portable Document Format), the file format created by Adobe for electronic document exchange. Specific PDF file formats can be ideal for specialist industriessuch as PDF/A for archiving, PDF/E for engineering and PDF/X for printing. Easiest Way to View a PDF: Use Your Browser Adobe Acrobat. The The PDF, or Portable Document Format, is a file type that uses compression and security features to keep documents looking the same regardless