Humus is a dark, organic matter that forms in soil from the decomposition of plant and animal material. It's rich in nutrients and helps improve soil structure, water retention, and aeration.

Rocks are naturally occurring solid materials made up of one or more minerals. They are formed through geological processes like igneous, sedimentary, and metamorphic processes.

Here's a simple way to remember the difference:

* Humus is made from living things that have decayed.

* Rocks are made from non-living minerals.