What is the difference between accuracy and precision in instrumentation?

Accuracy refers to how close a measurement is to the true value (systematic error), while precision indicates repeatability or consistency of measurements (random error). An instrument can be precise but not accurate (consistent readings, all offset from true value), accurate but not precise (readings average to true value but vary widely), or both accurate and precise. Calibration corrects accuracy; statistical methods assess precision. Both are expressed as percentage of span, reading, or full scale.