• noun the representation and measurement of numerical data by continuously variable physical quantities, as for the size of electrical voltages.


  • Of, pertaining to, or consisting of a signal or parameter which is continuously and infinitely variable. The characteristics, such as an amplitude or frequency, of an analog signal vary in a continuous and infinitely variable manner, while a digital signal has a range that is divided into a finite number of discrete steps. Although the analog coding of information, as opposed to digital, can better match a real-world source such as music or a panoramic scene, steps such as recording, copying, transmitting, and reproducing introduce greater and greater amounts of noise, distortion, and other interference. This is not a problem when recorded, processed, transmitted, and so on, digitally.
  • A variable whose magnitude closely or exactly follows another variable. For example, a voltage which fluctuates proportionally to a voice. Transducers, such as microphones, speakers, or photoelectric cells, make the appropriate conversions.