In this chapter, we covered the basics of ggplot2, distinguishing between different types of variables and introducing the best practices for visualizing them. You created basic one- and two-dimensional plots, then analyzed the differences between them. You used the Grammar of Graphics to change a basic visual into a better, more professional-looking visual.
In the next chapter, we will build upon these skills, uncovering correlations between variables and using statistical summaries to create more advanced plots.