According to the Wikipedia, “an e-book is the digital media equivalent of a conventional printed book.Such documents are either read on personal computers, or on dedicated hardware devices known as e-book devices or e-book readers.”
The origins of the electronic book can be traced as far back as 1946 when ENIAC (electronic numerical integrator and computer), the first computer, came online; and the most popular form of the electronic book today is the e-book as a component of the Internet. If the Internet is thought of as a giant library, storing all types of information, then websites are the individual books and magazines in all their varying sizes and content. Websites may include information, pictures, and links to other websites, much like the pages of codices contain printed text, pictures, and perhaps even references to other pages or books (such as footnotes). Many websites, such as online dictionaries and encyclopedias, are designed and utilized much like a printed media. In this way, certain online databases are often seen as electronic books in their own right. ( Bradley, 2002).
About the creation, some e-books are produced simultaneously with the production of a printed format though in many instances they may not be put on sale until later. Often, e-books are produced from pre-existing hard-copy books, generally by document scanning. It is also possible to do the opposite, it is possible to convert electronic book to a printed one.
This ‘new’ way of reading books has, as everything, it advantages and disadvantages, but gradually it use is increasing, it is possible to read books in the Internet or in a portable device.
James, Bradley ( 2002). The Electronic Book: Looking Beyond the Physical Codex