Sampling bias refers to the systematic error that occurs when the sample used in a study or survey is not representative of the entire population. This can happen when the sample is selected in a way that is not random, leading to a skewed or distorted representation of the population. This bias can significantly impact the validity and generalizability of the results, as it may not accurately reflect the true characteristics and opinions of the population. It is important to carefully consider and minimize sampling bias in research to ensure accurate and unbiased conclusions.