Humus, dark brown matter from the surface layer of the soil, is produced by the decomposition of plant and animal matter. Humus is rich in carbon and generally acidic due to its humic acid content. It increases the water storage potential of the soil and produces carbonic acid, which breaks down minerals.” This concept of the word humus is present in an entry by Brockhaus Enzyklopädie, a traditional German publication. Following this definition, we can say that humus is a fraction (part) of the soil, located in the most superficial layer, rich in organic matter and important for maintaining soil health, due to its multiple functions and properties. In this article we are going to classify some types of humus and their benefits for agriculture.