The layout manager in itself looks something similar to the above. There are so many settings at each level that let you modify every design element and possibilities at endless.
The green controls are for section level settings.
The red controls are for row level settings.
The purple controls are for column/inner column level settings.
The orange controls are for inner row level settings (Inner row is just another element that allows you to have better control and create flexible layouts within rows).
Sections (The top level container holding everything together, your page can have unlimited sections).
__Row (Second level container giving you much more control. Rows exists horizontally in your sections and you can have unlimited rows).
____Column (Third level container. Columns are standard based on grid. You can have maximum 12 columns and minimum of 1 column based on width).
______ Inner Row/Elements (Columns can have either elements or inner row, which can further have elements).