"PDF" is the abbreviation of portable document format, which means "portable document format". It is a file format developed by Adobe Systems for file exchange, which has nothing to do with applications, operating systems and hardware.
PDF file is based on PostScript language image model, which can ensure accurate color and accurate printing effect on any printer, that is, PDF will faithfully reproduce every character, color and image of the manuscript.
PDF is mainly composed of three technologies:
(1) generates and outputs graphics from PostScript;
(2) Font embedding system, which can transmit fonts with files;
(3) A structured storage system for binding these elements and any related content to a single file, with an appropriate data compression system.
Reference to the above content: Baidu Encyclopedia -pdf