analog information

Analog information is represented by continuously variable physical quantities, such as electrical potential or mechanical motion, that are analogous to the problem being solved. Humans receive analog signals through their senses, like sound waves and light waves. Before the advent of digital computers, information was primarily stored and processed in analog form using technologies like printing and photography.12

Analog computers, which manipulate physical quantities like voltage, were particularly adept at simulating dynamic systems in real time. Early examples include mechanical devices like the tide predictor and the differential analyzer. While electronic analog computers became prevalent in the mid-20th century, they were largely replaced by digital computers by the 1970s due to limitations in precision and programmability.13