PDFs

PDF (.pdf) is simply a file type, just like .txt, .xlsx, or .docx.  PDF stands for Portable Document Format.

PDF files typically start as another document type, such as a Microsoft Word document, and are then exported or saved as a PDF.  There are then two files containing the same content - a Word document (.docx) and a PDF (.pdf).  Many files found on the web are PDFs.  They are used for many reasons:

• Preserve the layout and content of the file.  A PDF will appear the same for any user, regardless of the device used - PC, Mac, tablet, phone, etc.
• Ensure all users can view the file.  If the file is a Word document (.docx), users on a Mac, tablet, or phone may not have Microsoft Word on their device, and will be unable to view the file.  Most web browsers have the ability to view PDF files without the need for additional software.
• A more professional presentation.  Presenting content as a Word document (.docx) forces users to open the file in Word, allowing them to edit content and see the markup of the file.  Presenting it as a PDF, however, provides the "finished product", with no backend visible.