Confidence intervals are a statistical tool used to estimate a range in which a true population parameter, such as a mean or proportion, is likely to lie. They provide a measure of the uncertainty or variability in the estimate, and allow researchers to make more informed decisions based on their data. Confidence intervals are typically calculated based on sample data and a chosen level of confidence, such as 95% or 99%. The width of the interval is determined by factors such as the sample size, variance, and distribution of the data. Overall, confidence intervals provide a way to communicate the precision and reliability of an estimate, and are commonly used in many fields including medicine, social sciences, and business.