What is a touchscreen?

A touchscreen is a surface that combines two functions: to receive inputs for a computer (say, tapping on an app) and to display the output (launching the app).

Capacitive touchscreen:

• Capacitive touch screen is the kind of display we see in our smartphones, laptops, and tablet screens.
• Capacitive screens are made up of multiple layers of glass and plastic, coated with a conductor material like indium tin oxide or copper. 
• This conductive material responds when contacted by another electrical conductor, like our bare finger. When we touch our screen, an electric circuit is completed at the point where our finger makes contact, changing the electrical charge at this location. Our device registers this information as a “touch event.”
• Once a touch event has been registered, the screen’s receptors signal this event to the operating system, prompting a response from our device. This is the application’s interface that we experience.
• Capacitive touch screens generally have a brighter, clearer appearance and are much more sensitive than resistive touch screens. We tend to see capacitive touch screens in more modern technologies like smartphones and tablets. They give us the ability to experience high-quality imagery that imitates reality.

Resistive touchscreen:

• Resistive touch screens work exactly how their name implies – with resistance to touch. A glass or hard plastic layer is blanketed by a resistive metallic layer that conducts charge. The two are separated by spacers in the screen so that when your finger presses firmly on the plastic protective layer, the two layers make contact changing the electric charge at that location, which causes the software to respond.
• Resistive screens are not as bright as capacitive screens because of their thick blue and yellow colored layers that make their interface appear darker than capacitive screens. 
• We often see resistive screens used on ATM machines, checkout stands, and POS (point of sale) terminals. They tend to be much more durable and affordable than capacitive screens, thanks to that hard plastic outer layer.

Why in news?

The ubiquity of smartphones owes itself to a human-machine interface that has become so intuitive as to make them extensions of our arms