E-books refer to publications that digitize information such as words, pictures, sounds and images, and handheld readers that integrate storage media and display terminals into which information such as words, pictures, sounds and images are implanted or downloaded.

E-books generally have two meanings, one is e-books, and the other is hand-held readers specialized in reading e-books. The main formats of e-books are PDF, EXE, CHM, UMD, PDG, JAR, PDB, TXT, BRM, etc. Many modern and popular mobile devices have the function of e-books. The mobile terminal can support the reading format of e-books. Common e-book formats are UMD, JAR and TXT.