This document discusses data visualization. It defines data visualization as making the story behind data come to life. Some key reasons to use data visualization are to tell a story or answer a question with data. The document outlines the ingredients, types, and history of important figures in data visualization. It provides examples of tools and resources for creating visualizations. Rules for effective visualization include showing rather than telling, using common icons, checking scale, applying color wisely, reducing clutter, and finding simplicity. The document encourages readers to practice visualizing their own data and choosing the best methods and tools.