What Is the comparison of reliability and validity?

Reliability refers to the consistency of a measurement, indicating how stable and dependable the results are when repeated under similar conditions. Validity, on the other hand, assesses whether a measurement accurately captures what it is intended to measure. While a test can be reliable without being valid (consistently producing the same result that is incorrect), a valid test is inherently reliable as it consistently measures the intended construct. In essence, reliability is about consistency, while validity is about accuracy.