The first quartile is a statistical term that represents the value below which 25% of the data points in a dataset fall. It is a way to divide a dataset into four equal parts, helping to understand the distribution of the data. The first quartile is often denoted as Q1 and is calculated by arranging the data in ascending order and finding the median of the lower half of the dataset. In a box plot, the first quartile is typically represented by the left edge of the box. This visual representation helps to quickly identify the spread and central tendency of the data. Understanding the first quartile is essential in fields like statistics, data analysis, and research, as it provides insights into the lower range of a dataset.