Learn in the textbookSignal Methods and Video Interfaces
DefinitionAnalog (アナログ) is a method that represents information by varying a quantity such as voltage continuously.
ExplanationIt turns quantities that naturally change smoothly, such as loudness or brightness, directly into signal strength. Noise picked up along the way arrives as part of the signal and is hard to separate from the original, so quality tends to drop as the transmission distance grows.
AnalogyOn a clock with hands, the hand keeps moving without a break even between the marks on the dial.
Memory hookIt comes from the Greek analogos, meaning "proportional", which matches a signal whose strength changes in proportion to the original quantity.