What is the grammar of graphics? It is a tool that enables us to concisely describe the components of a graphic and provides a strong foundation for understanding a diverse range of graphics. If you’re familiar with it, you may know the basic structure of a call to the ggplot() function. You can check out the visualization and data structure lecture for an introduction to the package. When you call ggplot, you should provide a data source, usually a data frame or tibble. Afterwards, you can build ggplot different mapping variables in your data source to different aesthetics. For example, there are colour, shape, size of points, the position of the x or y-axis, and so on. On the other hand, Tidy data refers to data arranged to make data processing, analysis, and visualization simpler.