What Kind Of Touchscreen Technology Is Behind Touchscreens That Only Register Presses With A Stylus?

These kind of touchscreen kiosks are at just about every supermarket now– when you pay for your purchase with a debit card for instance, you must make selections as to “cash back” and “correct total,” in addition to inputting your PIN number.
These screens have never worked for me by simply pressing them with my fingers. I always have to pick up and use the rubber-tipped stylus.
What is the technology driving this type of touchscreen interface?