Plotting bar charts in R, geom_bar vs geom_col

Plotting the Nightingale data made me realize that there are more to plotting a bar chart than first meets the eye. While a histogram visualize the distribution of a numerical variable, a bar plot visualize the relationship between a categorical variable and a numerical variable. ggplot has two functions for plotting bar charts, geom_bar and geom_col. In short, geom_bar() counts the categorical values for you, while geom_col() takes the summarized numerical value as input.