A touchscreen is a separate component from a display. Essentially, it is a piece of glass or plastic that goes in front of the display and accepts input from the user. It can either be flush with the display (like in a touch phone, or a GPS), or it can be a few inches in front of it (like on an ATM / ABM).
There are hundreds of different types of touchscreens, from many different manufacturers. At Monitech, we can replace many of them; please contact us and let us know what it is you need.