Ebooks, also called electronic books, digital books, full-text books, or online books, can be accessed 24/7 from any location.
Ebooks allow one to search the full-text of the books, which can be both an advantage and a disadvantage.
Image source: Plan and sections of a slave ship. Carl B. Wadstrom. 1794. As shown on slaveryimages.org, compiled by Jeromy Handler and Michael Tuite and sponsored by the Virginia Foundation for the Humanities and the University of Virginia Library.