What layer 1 doesn’t do is say what kind of visualization you want: scatterplot, bar graph, histogram, etc. For that you need layer 2: a geometry, or geom in gpplot-speak.

qplot(disp, mpg, data=mtcars) generates a scatterplot. A scatterplot from ggplot2 using the qplot () function. The qplot default starts the y axis at a value that makes sense to R.