Portable Document Format files (PDFs) are an efficient way of digitally sharing and outputting files across multiple platforms, including printing, losing no essential information in the transmission. Adobe introduced the file format almost 30 years ago.
Because PDF is now really an industry standard, a set of regulations was established and continues to be developed by the PDF Standards Committee. Specialized versions of PDFs have been created for specific purposes. PDF/a is for electronic document archives, and PDF/UA was formed for accessibility purposes. PDF/X drives general commercial printing, and variable and transactional documents use PDF/VT.