The first thing that you might be wondering is why the phrase, analog representation of digital waveforms. The truth is the digital waveform is simply a series of square waves. Video being an electronic presentation simulating human vision, needs to be displayed in an analog fashion for human interpretation. Analyzing a digital video stream of square waves displayed as binary 1's and 0's or other as digital forms, makes it challenging to determine if the sky is at 100 units or if a red shirt is of the correct hue, luminance and saturation. The most practical method so far developed is to transcode the digital information into an equivalent analog representation for display and measurement.
Video begins in the color TV camera.
These R, G and B video signals are all high-resolution high bandwidth video signals. The native format of all digital formats is Y Cr Cb. Eventually the Y or luminance will become what we all see and interpret as the brightness component of the displayed picture. The chrominance information of the picture is electronically embedded in the video signal as the Cb and Cr components. So, lets now look at some basic waveforms and understand what the displays really mean.