Here's a breakdown of the soil layers:

* Topsoil (O horizon): This is the uppermost layer, rich in organic matter, microorganisms, and nutrients. It's where plants grow best.

* Subsoil (A horizon): Below the topsoil, this layer is mostly mineral soil with less organic matter. It's often lighter in color than the topsoil.

* Substratum (C horizon): This is the parent material from which the topsoil and subsoil formed. It can be weathered rock, glacial deposits, or other materials. It's typically less weathered and more compact than the upper layers.

It's important to note that the layers may not be present in all soils, and the thickness of each layer can vary greatly.