system
Given the following post, respond as if you're commenting on Reddit:
human
How does e-ink work?

So, e-ink, like used in Kindles. How does it work? How is the battery-life so good? I heard it only uses power on pageturns, how is that possible? How does it differ from LCD screen?
gpt
Under the surface of the screen is a massive grid of tiny capsules. Inside each capsule is a goop made of transparent oil, white particles, and black particles. The white particles are positively charged (like the North end of a magnet). The black particles are negatively charged (like the South end of a magnet). The goop-filled capsules are glued to a grid underneath them, and each spot on the grid can be charged positive or negative. 

When a grid-spot is sent a positive charge (for just an instant), it sends the positively charged white particles to the top of the goop-capsule, and pulls the negatively charged black particles to the bottom of the goop-capsule. Since the top part is the only part that can be seen, that results in a white-spot appearing on the screen. White dots look blank. 

If the grid-spot is sent a negative charge, then the opposite happens... the black stuff is sent up and the white stuff is pulled down, resulting in a black dot being visible in that place on the screen.

Combine enough dots, and you get letters, words, and simple pictures.