The idea of ​​a folding screen is hard to believe because the smartphone screen comprises several layers usually. And most of the glass is not flexible. However, the folding screen is now possible because of technology that's gone a bit old now. It is often called Flexible Display Technology, built around the OLED (OLED) light retrieval screen.
A typical OLED screen is made of organic material that emits light when electricity passes through it. They do not need a backlight to function, and as a result, they can be made relatively thin to the point where they become flexible, forming a flexible screen basis.