Portable Document Format (PDF) is a type of document created by Adobe back in 1990s. The purpose of this file format was to introduce a standard for representation of documents and other reference material in a format that is independent of application software, hardware as well as Operating System. PDF files can be opened in Adobe Acrobat Reader/Writer as well in most modern browsers like Chrome, Safari, Firefox via extensions/plug-ins.
PLYPolygon File Format
PLY, Polygon File Format, represents 3D file format that stores graphical objects described as a collection of polygons. The purpose of this file format was to establish a simple and easy file type that is general enough to be useful for a wide range of models. PLY file format comes as ASCII as well as Binary format for compact storage and for rapid saving and loading.