How do analog computers differ from digital computers?

Analog and digital computers differ primarily in how they represent and process information.

• Analog Computers: These devices represent quantitative information using continuous physical magnitudes, such as voltage, fluid pressure, or mechanical motion. As pioneered by Vannevar Bush with his Differential Analyzer, these machines solve problems by allowing these physical variables to change freely in a way that mimics the system being modeled. They are particularly effective for real-time simulations of dynamic systems but are generally limited in precision and difficult to program for general purposes.123

• Digital Computers: In contrast, digital computers process information in a discrete form. They represent data using a limited set of values, typically binary code consisting of 0s and 1s, often implemented through two distinct voltage levels. By manipulating these discrete digits according to stored instructions, digital computers can perform complex tasks ranging from data organization to the simulation of dynamic systems.453

By the 1970s, digital computers had largely replaced analog devices due to their superior power, speed, and versatility.2