How do touchscreens work? | Types of touchscreens compared
O nce upon a time, the way to get a computer to do something useful was to feed it a stack of cards with holes punched into them. Thankfully, things soon moved on and, by the end of the 20th century, you could get a computer to do things simply by pointing and clicking with a keyboard and a mouse. But the real revolution in making computers easy to use has happened only in the last decade or so—with the arrival of touch-sensitive screens . Most smartphones, ebook readers, and some MP3 players already work with simple, touch controls—and some laptops work that way too. Touchscreens are intuitively easy to use, but how exactly do they work?
A touchscreen is a bit like an invisible keyboard glued to the front of your computer monitor. To understand how it works, it helps if you know something about how an ordinary keyboard works first. You can find out about that in our article on computer keyboards, but here's a quick reminder...
Essentially, every key on a keyboard is an electrical switch. When you push a key down, you complete an electric circuit and a current flows. The current varies according to the key you press and that's how your computer figures out what you're typing.
