The technology for touch screens comes in a variety of different forms. There is resistive, surface acoustic wave, capacitive which includes surface capacitance and projected capacitance touch (PCT), infrared, strain gauge, optical imaging, dispersive signal technology, and acoustic pulse recognition. PCT touchscreen technology is used in a wide range of applications including smart phones, kiosk, and point-of-sale systems.
Most touch screens are typically operated by using the finger to interact with the images on the screen. However in some situations touch screens can suffer from the problem of fingerprints on the display. Also the images all buttons that need to be selected on the touch screen can be very small, such as in smart phones, making it difficult to use the finger. In that situation a stylus is quite often use. Even the fingernail can be used as a stylus if it is long enough.
Touch screens combined with haptics provides the user feedback when certain keys are pressed on the screen. For example the Samsung Omnia smart phone can make a slight vibration and buzzing sound to let the user know that a key has been selected. Study shows that is this reduces input errors and increases input speed.
Some people do find touch screens a little bit difficult to use with their fingers where the display is small. However when ergonomically designed, touchscreens make it easier for the user to interact with the device or gadget while saving space which would otherwise be used with a keyboard or mouse. Touch screens are definitely here to stay.