How Video Works, 3rd Edition

11Digital Theory

An analog signal is a sine wave. Like an ocean wave in constant motion, an analog signal continually changes over time. In fact, the term analog is actually derived from the word analogous because of the signal’s analogous relationship to the sine wave (Figure 11.1). Digital information, on the other hand, is fixed and absolute and does not change over time. When information is digitized, the data remains as it was originally recorded.

Analog Domain

Figure 11.1 Sine Wave

In the Introduction of this book, we said that sight and hearing are responses to energy waves, which is an analog phenomenon. Video was originally developed ...