PDF stands for Portable Document Format.

Portable Document Format (PDF) is a file format used to present documents in a manner independent of application software, hardware, and operating systems.^[2] Each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it. In 1991, Adobe Systems co-founderJohn Warnock outlined a system called "Camelot"^[3] that evolved into PDF.

While Adobe Systems made the PDF specification available free of charge in 1993, PDF was a proprietary format, controlled by Adobe, until it was officially released as an open standard on July 1, 2008, and published by the International Organization for Standardization as ISO 32000-1:2008,^[4][5] at which time control of the specification passed to an ISO Committee of volunteer industry experts. In 2008, Adobe published a Public Patent License to ISO 32000-1 granting royalty-free rights for all patents owned by Adobe that are necessary to make, use, sell and distribute PDF compliant implementations.^[6] However, there are still some proprietary technologies with published specification defined only by Adobe, such as Adobe XML Forms Architecture, and JavaScript for Acrobat, which are referenced by ISO 32000-1 as normative and indispensable for the application of ISO 32000-1 specification.^{[7][8][9][10][11]} The ISO committee is actively standardizing many of these as part of ISO 32000-2.