This document discusses histograms and bullet charts. Histograms are used to show the distribution of a range of values, such as exam grades or salaries, and indicate whether the distribution is normal or skewed. Bullet charts measure performance against an actual target, such as sales by category. They tell the story of why some units are hitting goals while others fall short. The document explains that exploratory analysis uses data visualization to understand patterns in the data, while explanatory analysis has a specific point to demonstrate to an audience using additional context and explanation.