A novel human interface excellent in operability is provided. Furthermore, a novel data processor excellent in operability is provided. Furthermore, a novel data processor, a novel display device, or the like is provided. An input/output device that receives image data and supplies positional data, and an arithmetic device that supplies the image data and receives the positional data are included. The input/output device includes a first region, a second region, and a bend portion between the first region and the second region. Each of the first region and the second region includes a display portion and a positional data input portion that overlaps the display portion. The arithmetic device includes an arithmetic unit and a storage unit that stores a program to be executed by the arithmetic unit.