A box-and-whisker plot, also known as a box plot, is a graphical representation used to display the distribution of a dataset. It summarizes key statistics, including the minimum, first quartile, median, third quartile, and maximum. The "box" shows the interquartile range (IQR), which contains the middle 50% of the data, while the "whiskers" extend to the smallest and largest values within 1.5 times the IQR. This type of plot is useful for identifying outliers and comparing distributions between different groups. By visualizing the spread and center of the data, box-and-whisker plots help in understanding variations and trends effectively.