Resistive touch technology is built up by a bottom glass with two conductive layers on top that are separated by spacers. When a force is applied from a human finger or stylus the two layers are pressed together. This creates a connection between the layers and the resistance is changed which can be determined as coordinate by a controller circuit.
There are more advanced versions of resistive touch screen such as glass-film-glass (GFG) and true-flat frameless touch screens. GFG means that a very thin sheet of glass or heavy duty film is placed on top of the touch screen to increase its resistance against scratches, high temperatures and makes it possible to use chemicals to clean it. A true-flat resistive touch screen is made to look like a PCAP touch