Natural resources can take the form of food, materials or sources of energy. Trees, water, and chalk are all examples of natural resources than can be used as raw materials in themselves, or to produce other materials. They are all needed to produced paper, for example. Some natural resources that are used as materials in themselves can also be used as sources of energy. Such natural resources include trees, water, coal and crude oil. Uranium, natural gas and wind are examples of natural resources that are only used as sources of energy. 

Natural resources that are used either as materials or energy sources can be divided into renewable and non-renewable resources. Renewable resources include things like biomass, wind, water and solar radiation. They replenish after they are used or consumed. In contrast, non-renewable resources include things such as metals, minerals, fossil fuels and uranium. They do not replenish after being used, which means that their supplies are limited.

Natural resources can also be divided into material and immaterial resources. Material resources are tangible things, such as trees and water, whereas immaterial resources are intangible things, such as sunlight or a cultural landscapes. The table below shows examples of various material natural resources.

MATERIAL NATURAL RESOURCES

Use	Renewable resources	Non-renewable resources
Energy	wood, energy plants, peat, biogas, waste	oil, natural gas, coal, uranium (nuclear power), peat
Material production	wood, water	minerals, ores, rock, gravel, sand
Food	plants, fungi, fruits, berries, game animals, fish, water	some minerals