Update : November 15, 2022

Definition

• Analog may stand for “a person or an object which may be compared to another”.
• An analogy is a comparison of two things that are similar.

Analog devices

• An analog device uses information represented by a continuous variable.
• An analog thermometer measures temperature via the expansion of the mercury in its bulb.
• The analog speedometer displays the speed of a car via the needle on its dial.
• Some early computers are analog (e.g. Differential Analyzer).
  The later computers are mostly digital.
  Some computer systems are hybrid.

Converters

• There are tools to convert analog signals to digital, and vice versa.
• ADC is a tool to convert Analog to Digital.
• DAC is a tool to convert Digital to Analog.

• The sounds produced by a musical instrument are analog.
• Analog information may be digitized by using appropriate sampling techniques.