Pdf 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, and portable document format is an electronic file format. Compared with other electronic document formats, PDF has many advantages.

PDF file format can encapsulate characters, glyphs, formats, colors, graphics and images independent of devices and resolutions in one file. Format files can also contain hypertext links, sounds, dynamic images and other electronic information, support super-long files, and are highly integrated, safe and reliable.

The full name of jpg is JPEG, which is a format of pictures. JPEG pictures store a single bitmap in 24-bit color. JPEG is a platform-independent format that supports the highest level of compression.

For ordinary readers, e-books made of PDF have the texture and reading effect of paper books, which can vividly show the original appearance of the original book, and the display size can be adjusted at will, providing readers with personalized reading methods.