All about Computer Monitors
How do Touch Screens Work?
This resistive system consists of normal glass, (which is why it can break so easily) and covered in as metallic layer.
When someone touches the screen the two layers make contact in that exact spot.
You can now get touch screens on computers, laptops, ipods, ipads, and most smartphones
Here's a video on how to take apart a ipad touch.
Apple iPad TearDown & Take Apart Repair Directions by DirectFix.com
How Touchscreen works