1, TXT- text format

Txt is a text format attached to Microsoft operating system, and it is the most common file format. It was widely used as early as the DOS era, mainly storing text information, that is, text information.

2.PDF- Portable Document Format

PDF files are common in Windows, Unix and apple's Mac OS operating systems. This feature makes it an ideal document format for electronic document distribution and digital information dissemination on the Internet. More and more e-books, product descriptions, company announcements, online materials and emails are using PDF files.

3. Electronic publications (electronic publishing)

The EPub file uses XHTML or DTBook (an XML standard proposed by DAISY Consortium) to represent the text, and wraps the file content in zip compressed format. EPub format contains optional digital rights management (DRM) related functions.

4、RAR

RAR is a patented file format, which is used for data compression, archiving and packaging. The developer is Eugene Rochelle (Russian: евгениклареви).

5、DjVu

DjVu is a file format for saving books, similar to PDF. Its principle is to divide the image into foreground layer and background layer for compression.