What is the difference between analog and digital?   In TV context analog means that the picture (and sound) is sent as a modulated electromagnetic wave. That means that there is a carrier wave of specified frequency and some of it’s properties like amplitude (how high the wave is), waveform or wavelength are slightly changed (modulated) to transport the information. This is how TV signals were transmitted over the last 50 years since the beginning of TV broadcasts. It worked well but the drawback of this is that an electromagnetic wave being transmitted through the atmosphere, which is an electrically active area, is subject to disturbance and alteration. Only too often what is received over the antenna is not what was sent from the station. Also electrical activity within your home might disturb the signals. This accounts for the all too familiar TV disturbances like ghosts, snow or a general unclear picture or in extreme weather conditions like a thunder storm you might not receive any signal at all.

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