A decile is a statistical term that divides a dataset into ten equal parts, allowing for the analysis of data distribution. Each decile represents 10% of the data points, helping to understand how values are spread across a range. For example, the first decile (D1) includes the lowest 10% of values, while the tenth decile (D10) includes the highest 10%. Deciles are commonly used in various fields, such as economics and education, to assess performance or income levels. By comparing different deciles, researchers can identify trends and disparities within a population, such as income inequality or academic achievement among students.