Provided are a display device with low power consumption which enables reduction of an operation processing amount of a GPU and which does not require a storage device for storing image data corresponding to one screen, and a display system using the display device. The display device is constituted by pixels each including storage circuits, an operation processing circuit, and a display processing circuit and circuits each having a function of storing image data in arbitrary storage circuits. The display system is constituted by the display device and an image processing device including the GPU. Image data is formed for each structural component through operation processing in the GPU in the display system. The formed image data is stored in the corresponding storage circuit for each pixel. The stored image data is subjected to composition processing by the operation processing circuit for each pixel. Then, the image data is converted into an image signal in the display processing circuit.