Accuracy
Accuracy describes closeness to the accepted or true value.
Precision
Precision describes how closely repeated measurements agree with one another.
Uncertainty
Uncertainty expresses the range within which the measured value is reasonably expected to lie.
Why uncertainty is useful
Reporting uncertainty is not admitting failure; it communicates how much confidence the measurement deserves.
Source trail: NIST: SI units
This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.