E-book is a form of digital book, also known as "e-book" or "digital book". They are stored as electronic files in computers, smart phones, tablets and other electronic devices, and can be downloaded and read through the Internet. Different from traditional paper books, e-books use electronic ink screens or color displays to present content, which can be read by e-book readers, smart phones, tablets and other devices.

E-books have many advantages, for example, they can be easily carried and stored, read on different devices, and purchased and downloaded on the Internet. In addition, the price of e-books is generally cheaper than traditional paper books, because e-books do not need printing and transportation costs.

In addition, e-books also have some special functions, such as searching, bookmarking, highlighting and taking notes, which can help readers better read and understand the contents of books. At the same time, e-books can also be updated and expanded to keep the latest and most comprehensive information.

In a word, e-book is a convenient, practical and sustainable digital book form, which is gradually changing people's reading methods and habits.