A P-value is a statistical measure that helps determine the significance of results in hypothesis testing. It quantifies the probability of observing the data, or something more extreme, assuming that the null hypothesis is true. A low P-value (typically less than 0.05) suggests that the observed data is unlikely under the null hypothesis, leading researchers to consider rejecting it in favor of an alternative hypothesis. In simpler terms, the P-value helps researchers understand whether their findings are likely due to chance or if they indicate a real effect. It is an essential tool in fields like medicine, psychology, and social sciences for making informed decisions based on data.