Scatterplots are one of the oldest and most commonly used methods to
project high-dimensional data to 2-dimensions. In this method, an grid of parallel projections of the data are generated.
Each of these is a simple
plot for the two dimensions it
represents. The horizontal dimension of a scatterplot is controlled
by the column it resides in, and likewise the vertical dimension is
controlled by the row. At the top of each column and at the left of
each row is a label that shows what dimensions that row / column
represents.