From the structure of the screen, we can divide the screen into three parts. From top to bottom, there are cover glass, touch glass and display glass.

1. In-cell

2. On-cell

Put the touch sensor above color filter. To be exact, the touch sensor is between top polarizer and color filter. Three layers of glass, cover glass, touch sensor glass and display glass. 

3. OGS

Assemble the touch sensor and cover glass in on glass. Two layers, they are cover glass with touch sensor and display glass