Vertical blanking
Like Horizontal blanking, this term comes from analog technology. The time required to reposition the electron beam from the lower right hand corner, to the upper left hand corner is the vertical blanking. In the digital world, the vertical blanking is the time between video frames. For example, if transmitting at a rate of 30Hz, a new video frame will be sent every 1/30 of a second. If the entire time needed to transmit the frame is 1/60 of a second, another 1/60 of a second is left over before beginning the transmission of the next video frame. The vertical blanking is accomplished by inserting idle characters.