The upper layers of the soil developed from many different rock materials under the influence of climate and fauna. Solid rock and rock parts of all sizes were worn down by rivers or glaciers and over thousands of years crumbled and decomposed to form the soil as it is now. These processes are still going on and in Swiss soils changes in composition and thickness of soil layers occur in most cases within relatively small distances. On one hand, the glacial times have only just a short time ago (seen from the perspective of the Earth's total history) monumentally changed the uppermost layers of the earth's crust, on the other hand, the strongly inclined topology results in frequent and continuing changes by surface earth movements (erosion and accumulation). This means that within the space of a few metres an important ground feature such as its water-retention capability can change extensively.
Without soil, a terrestrial ecosystem is not possible. Soils form an indispensable resource for higher life forms, for plant growth and thus for primary products such as foodstuff, raw materials and fuels.
In the Swiss map of soil suitability (scale 1:200,000) the mapped unities correspond tosoil associations of a maximum of 6 soil forms. A soil type and maybe a subtype describe a soil form. Three important soils of Switzerland are:

Cambisol: Characterised by on-going weathering of the frequently already pre-weathered exposed material down to a depth of ca. 60-150 cm. The typical brown colouring is due to sufficient air being present in the soil to allow the formation of iron oxides. It is the most frequent type of soil found in the lower parts of Switzerland. It is mostly very fertile and suitable for agriculture in areas that are not too steeply inclined.

Gleysol: soil characterised by being permanently or periodically waterlogged by ground water, flowing or stagnant water. It is mostly fine textured and rich in clay-size particles. The iron is partly existent in ferrous form, giving the soil a pale grey, blue or green colouration. This soil occurs all over Switzerland, mostly only in small areas in valley plains, plateaus, hollows and in locations at the foot of inclines. In a non-drained state it is chiefly suitable for hay-meadows.

Histosol: Black soils made up of dead organic material over impermeable mineral layers, In the original state it is mostly waterlogged with groundwater or flowing or stagnant water, but in many places today it is drained. It is present in the whole of Switzerland, however mostly only in small areas. In a non-drained state it is at its best usable only as litter meadow. Draining the groundwater and subsequent agricultural usage results in decomposition of the organic material followed by sinking of the ground level.