1. Resistive Touch Screens

Resistive touch screens were one of the first technologies used widely. They detect touch through pressure on the screen.

Working Principle of Resistive Screen

Double conductive layers in the screen When they are pressed together the signal tells the touch location.
But that is not accurate, it also demands strength to press and, as a default only supports single touch with sluggish response.
Soft plastic (like PET, soft and low hardness: 2H-3H) make up the surface of the material covering it.
Cheap, no signal interferences and very well suited for outdoor as well as industrial usage.

Early phones used resistive screens that dented when pressed with a stylus

2. Capacitive Touch Screens

First up we have Capacitive touch screens, current Number 1 in popularity with devices like smartphones and tablets.

Working Principle of Capacitive Screen

Touch screens are the type that senses the capacitive field of human body in which these screens identify tapped positions.
Usually the surface is covered with tempered glass of high hardness >8H so that it is durable against scratching (seldom scratched).
Screen are the capacitive type supports multi-touch, has fast response devices and high light transparency, but it is vulnerable to electrical interference.
They are very common in devices that require a lot of user interaction like cell phones, tablets and even gaming consoles.

Capacitive screens dominate the market

3. Electromagnetic Touch Screens

Electromagnetic touch screens use an innovative solution to touch screen technology.
They use the electromagnetic induction layer and a pen to keep your screen you touch in question
The sensor is into back or bezel of the screen. 

These panels can be integrated into various display sizes. Their back-mounted design ensures durability.

The stylus contains a coil that detects magnetic fields from the panel’s coil array, determining the pen’s position and movement.