Soil formation is the result of long processes (paedogenesis) that are generally based on the alteration (that is change) of inorganic (minerals and rocks) and organic compounds (plants and dead animals or substances produced by them, like leaves and faeces) that are present in the area, their deposit and the subsequent formation of new minerals and organic molecules. The final composition and structure of a soil depend on the following factors: the parent rock, i.e. the original material of the soil; the climate; water and temperature; soil sun exposure; the activity of biotic entities; the height; the length of time and human activity.