We use different operating languages and dialogue with the digital world on different devices. Different languages not only connect us with the digital world, but also clearly draw our boundaries with the digital world. Since we first connected to the Internet, the way we have interacted with the digital world has changed from external devices like keyboards and mice, to touch controls, to gesture controls and so on.

With the development of the computer, the interactive interface changed from the initial text interface to the graphical interface. Based on the visualization of operations, the interactive interface becomes the direct medium through which electronic devices connect the operator to the digital world.

On the one hand, the transition from text interface to image interface is a watershed leap in interactive interface. On the other hand, the shift from keystroke devices such as mouse and keyboard to multi-touch with fingers is also a qualitative leap. The game industry has evolved to the point where games can even be played through motion-sensing on the Wii and Switch.

The evolution of interaction and interfaces has not changed the original purpose of using devices -- use tools to talk with the digital world. We use swipe language, tap language, or wave language to communicate with our gadgets, and they respond to our statements with interface changes. In this process, the user feeds into the machine, and the machine also feeds back to the user.

I want to make a clearer distinction between the digital world and the real world, to better highlight the difference between User and Machine. The image presented on the screen of the mobile phone is recorded as the words of the reply of the electronic device. The Paper Roll, which records what one does while using a touch-screen phone, represents the real world's operating language, and is, therefore, something that can be directly touched. On the Paper Roll, the horizontal axis is the position touched when manipulating the screen, and the vertical axis is the time. Mapping location and time onto a piece of paper records what we ask for our devices.