Compost is a mix of decaying nutrient-rich soil with a medium density that is naturally made using oxygen, bacteria, water, and organic materials. Compost combines green matter, such as food products and lawn clippings, with the brown matter, such as twigs and dry leaves.
This combination then begins to deteriorate in the composting process. The materials break down into rich soil, which is predominantly used to refresh depleted soils just before planting a new set of crops.
Soil is the top layer of the earth. Soils are made from various proportions of sand, silt, clay, and small amounts of organic matter. Soil formation occurs when many things happen to interact over a period of up to 1,000 years. Air, water, decaying plant life, rock, animal life, and chemicals all interacting, as well as plant roots and lichens wearing down rocks, creating new soil, and roots and oxygen helping to loosen and aerate it.
After several growing seasons using this soil, you will need to amend the soil with compost and add soil to get the nutrient levels back to a suitable level. That is where compost becomes important, making it richer and easier to grow things in.