Box plot

http://www.itl.nist.gov/div898/handbook/eda/section3/boxplot.htm

A box plot graph shows numerical data for different variables on an x and y axis. The lines extending outside of the upper and lower part of the box plot are called whiskers and they represent variability outside of the box plot. In the box plot above the x axis represents the comparison of four machines for energy output and the y axis represents the energy response. From the information provided above machine three has the highest energy response, machine two the second, machine one the third highest and machine four has the least energy response.