Deviation, or variation, refers to the difference between a value and a reference point, often the average or expected outcome. It is commonly used in statistics to measure how much individual data points differ from the mean. Understanding deviation helps identify trends, anomalies, and the overall distribution of data. In various fields, such as manufacturing and quality control, deviation is crucial for assessing performance and ensuring consistency. A small deviation indicates that results are close to the expected value, while a large deviation may signal potential issues or the need for further investigation.