Free E-books is a popular tag as people are interested in obtaining free copies or editions of electronic books, which are books that can be read on a computer or other electronic device. Several factors may account for this interest.
First, while the cost of E-books is generally less than for a physical copy, there are complaints of price given the comparative cost of production and distribution. Thus, free is good. Second, unlike ink and paper, there is no standard format for electronic books and digital rights management ("DRM") may not allow works to be shared with others who have the same device. In contrast, free e-books generally come without DRM.
Finally, there are a large number of websites that offer free e-books. Some of the more respected include The Online Books Page from the University of Pennsylvania and Project Gutenberg, perhaps the oldest such site.