A confidence interval is a range of values used to estimate an unknown population parameter, such as a mean or proportion. It provides a measure of uncertainty around the estimate, indicating how confident we are that the true value lies within this range. For example, a 95% confidence interval suggests that if we were to take many samples, about 95% of the calculated intervals would contain the true parameter. The width of a confidence interval depends on the sample size and variability in the data. Larger samples generally produce narrower intervals, reflecting more precise estimates. Researchers often use confidence intervals in fields like statistics, healthcare, and social sciences to communicate the reliability of their findings.