Chances are, you’ve been hearing a lot about E-Readers these days. They're devices designed primarily for the purpose of reading digital publications (books, newspapers, magazines, etc).  As discussed in this episode, E-Readers vary in design and presentation. Perhaps the most popular permutation of the E-Reader comes in a tablet form factor with an E-Ink screen. E-Ink is a revolutionary display method based on electronic paper. The technology revolves around charging transparent microcapsules suspended in a clear fluid. These capsules contain negatively charged black and positive charged white particles. When positive electricity is applied, the white particles move to the top, when negative electricity is applied, the black particles move to the top. To put it simply, these capsules can be "turned on or off" to display shapes on the screen such as text or a grayscale image. However, the rise of tablet computers has created a new kind of LCD (liquid crystal display) based E-Readers as well - such as the Apple iPad or the Barnes & Noble Nook Color. While each device has its pros and cons, the biggest negative against LCD based E-Readers is eye fatigue due to their backlit screens. By contrast, E-Ink closely recreates the experience of reading ink on regular paper, which lessens eyestrain.