Lots and lots and lots of colored boxes, right?
Each box represents a single file or a folder on your computer. Each box is sized in the display relative to the amount of space it takes up on your computer. Big boxes represent big files or folders, so they take up a lot of space in the display. Little boxes represent small files and folders, so they take up very little space in the display. Makes sense, right?
Now let's look at one of those boxes in detail and see what all the numbers and colors mean.