The majority of the devices use display technology from E Ink, resulting in a monochrome, nonbacklit page that looks far more like a printed page than the images on an LCD screen. And, as with a printed book, you can read in just about any light, including bright sunlight, but when there's no light, you must turn on a lamp to read.
A few devices use a thin-film transistor (TFT) type of LCD instead. Tablet-type e-readers incorporate highly reflective color touch screens that, like a computer monitor or digital camera LCD viewfinder, transmit light directly to your eye. That makes them difficult to read in direct sunlight, but easy to read in low-light conditions.
Most e-readers are small and light enough so that you can hold and read them with one hand, just as you would a paperback. Text is usually displayed one page at a time, formatted to look like a traditional book. To turn the page, the reader either pushes a button or swipes a finger across the screen.
Depending on the brand, you can change the size of the font, specify the typeface, select a set of foreign language characters, zoom in on photos and graphics, or rotate the page orientation from portrait to landscape. If you encounter an unfamiliar word, pressing a button or touching an icon will display the built-in dictionary's definition.
E-readers come with either a physical or a virtual keyboard for recording notes or annotations that can be linked with a word, sentence, paragraph or section, or to search for a specific word or reference. If you want to return later to a certain page, you can bookmark it electronically for easy retrieval.
Depending on the device, you can highlight or save selected text, view other readers' highlights of significant passages, surf the Web, send and retrieve e-mail, directly access Wikipedia, lend e-books to a friend, borrow from an e-book library, or transfer an e-book to your PC, smartphone or other device. Many e-readers also allow you to download and play MP3 music while you're reading, have your book read out loud via a speech-to-text capability, view your photo gallery, or join a social network of like-minded readers to rate, recommend or review e-books you love or hate.
All e-readers have the capacity to download and store hundreds or thousands of e-books and can help you organize your e-books into searchable collections and categories. Some enable expansion via optional SD or microSD memory cards, and many allow you to permanently archive your purchased e-books in the cloud so you can retrieve them at anytime, anywhere and on any device.
Printed books are still useful