People rely heavily on data to understand, communicate, and make decisions. By tapping into the power of our visual processing system, data visualizations -- maps, infographics, flow charts, word clouds, and network diagrams -- can massively enhance our ability to analyze and understand patterns in order to make data-driven decisions. Information visualization researchers examine how people interpret and communicate data. We develop novel visualization techniques and tools to help people more efficiently explore data, extract insights from data, and tell stories with data.