What converts analog to digital?

• A. Sampling
• B. Dithering
• C. Compression
• D. Filtering

Answer: (A)

Converting an analog signal to digital begins with sampling, which means measuring the signal’s amplitude at regular time intervals. This step turns a continuous-time waveform into a sequence of discrete-time values, providing the time-domain representation needed for digital processing. After sampling, those amplitudes are typically quantized to a finite set of levels to create actual digital numbers. Dithering can be used during or after quantization to lessen perceptible errors, while filtering and compression serve other purposes—filtering shapes or cleans the signal, and compression reduces data size—rather than performing the basic conversion. So the essential first move in analog-to-digital conversion is sampling.