The term resource has different meanings and implications based on the context and time. A resource can be both natural and made items that we value and use to produce goods and services that satisfy needs and wants. Resources can be classified as renewable (rainwater), recyclable (forests, fish) and non-renewable (fossil fuels). The four economic resources (factors of production) are land, labour, capital and enterprise. Production usually requires the combination of resources. See environmental resources in this glossary.