How do computers convert analog signals into digital information?

Computers convert analog signals into digital information through a process called analog-to-digital (A/D) conversion. This process is essential because analog signals vary continuously, whereas digital systems require discrete values represented by binary code, consisting of 0s and 1s (bits).12

The conversion involves three primary steps:

• Sampling: Based on the Nyquist sampling theorem, the continuous analog signal is measured at regular intervals. To accurately reconstruct the original signal, the sampling rate must be at least twice the highest frequency present in the signal.3
• Quantization: Each sampled amplitude is mapped to a finite number of discrete levels. Because this assigns variable amplitudes to a limited set of values, it is considered a "lossy" process that introduces some signal distortion. The number of levels used is typically a power of 2 (e.g., 256 levels) to facilitate binary representation.4
• Bit Mapping: The quantized levels are encoded into a binary sequence. For example, 256 levels require 8 bits per sample. The resulting digital data can then be processed, stored, or transmitted by the computer.54