The bar code is printed on the back cover of the book, which stores the relevant information of the book.
A magnetic stripe is a thin layer of material (also called pigment) composed of aligned iron oxide particles. Closely bonded together with resin adhesive, and bonded to non-magnetic base media such as paper or plastic.
A magnetic stripe is essentially the same as a magnetic tape or disk used in a computer. It can be used to record letters, characters and numerical information. It is firmly combined with plastic or paper by bonding or heat sealing to form a magnetic card. A magnetic stripe usually contains more information than a long bar code. The magnetic stripe can be divided into three independent tracks, called TK 1, TK2, TK3 and TK 1, and 79 letters or characters can be written at most. TK2 can write up to 40 characters; TK3 can write up to 107 characters.