What Does Analog Mean?
Analog, in the context of technology, refers to signals derived from physical phenomena that also may be interpreted as signals representing physical measurements. Light or visual input, for example, is an analog signal, so to capture video, its analog signal must be scanned and then translated into fluctuating electronic pulses.
Record players, VCRs and cassette players are examples of analog devices because they record information in a linear manner, and they read physical data from a media device by scanning it. An analog signal is characterized by regular sinusoidal curves or sharp, irregular spikes, while digital signals are normally constant in amplitude and characterized by flat signal waves, like plateaus.