Video generally refers to various technologies that capture, record, process, store, transmit and reproduce a series of still images in the form of electrical signals. When the continuous image change exceeds 24 frames per second or more, according to the principle of persistence of vision, the human eye cannot distinguish a single static picture; it seems to be a smooth and continuous visual effect. Such a continuous picture is called video. Video technology was first developed for television systems, but it has now evolved into various formats to facilitate consumers to record video. The development of network technology has also caused the recorded video clips to exist on the Internet in the form of streaming media and can be received and played by computers. Video and film belong to different technologies. The latter uses photography to capture dynamic images as a series of still photos.