The term ebook (or e-book) is a conjunction of the words “electronic book,” and refers to the text of a book which made available digitally, usually downloaded, and accessed through a device such as a computer, a smartphone or, popularly, a portable, dedicated ebook reader.
The invention of the ebook is generally credited Michael Hart. In
1971, when given a valuable chunk of computer time on a Xerox
mainframe, Hart set out to begin storing the vast contents of our libraries in electronic formats that would
be searchable and retrievable. Hart named his efforts Project
Gutenberg, after the inventor of the printing press.
Because the value of electronic databases for research purposes, libraries were early adopters of the technology. But it took nearly thirty years for the idea of the ebook to take firm hold with
the consumer. Now ebooks are widely used and widely available.
There are a number of competing ebook formats and handheld ereader devices, including Barnes & Noble’s NOOK, Amazon.com’s Kindle, Apple iBooks, Microsoft
Reader, Adobe PDF, and more. Some of these formats are proprietary (for
example, you can’t read a NOOK ebook on a Kindle), and they offer
slightly different capabilities.
Like their print book counterparts, ebook readers are highly portable.
One clear advantage of the ebook reader over its print progenitors is that the device can contain literally hundreds of books on a single
device. Ebooks are searchable and some are “enhanced” with extra
material, such as photos or video.
There are many outlets from which to download ebooks--many booksellers
and publishers offer that option. Some, like bn.com, offer a selection of free ebooks to customers as well. Michael Hart’s Project
Gutenberg offers free ebooks for works that are in the public
domain. Google ebooks also offers a large selection of free ebooks--they claim a list of "nearly 3 million."