Touch displays come in several types, each using a different method to detect touch. The main types include:

1. Resistive Touchscreen

How it works: Two conductive layers (usually ITO-coated) separated by a small gap. When pressed, they make contact, registering the touch.

Pros: Works with any object (finger, stylus, glove), low cost.

Cons: Lower clarity and multi-touch support; pressure needed.

2. Capacitive Touchscreen

How it works: Uses the body’s natural conductivity to detect changes in an electrostatic field.

Variants:

Surface Capacitive

Projected Capacitive (P-Cap) – supports multi-touch, used in smartphones.

Pros: High clarity, multi-touch, responsive.

Cons: Requires conductive input (bare finger or capacitive stylus).

3. Infrared (IR) Touchscreen

How it works: IR LEDs and photodetectors create a grid of invisible light across the screen. Interruptions register as touch.

Pros: Works with any object, no physical contact needed.

Cons: Prone to false touches (dust/insects), bulkier.

4. Surface Acoustic Wave (SAW)

How it works: Sends ultrasonic waves across the screen. Touch disturbs the waves, which is detected.

Pros: High image clarity, durable glass surface.

Cons: Can be affected by water, dust; more expensive.

5. Optical Imaging

How it works: Uses cameras and infrared light to detect touch by triangulating finger position.

Pros: Works on large displays, multi-touch capable.

Cons: Lower precision; ambient light can interfere.

6. In-Cell / On-Cell Touch

How it works: Touch sensors are integrated directly into the display layers (especially in OLED and high-end LCDs).

Pros: Thinner design, better optical quality.

Cons: More complex manufacturing, harder to repair.