* Renewable resources: These are resources that can be replenished naturally over a relatively short period of time. Examples include solar energy, wind energy, hydropower, biomass, and timber (when harvested sustainably).

* Nonrenewable resources: These are resources that are formed over geological timescales and are finite in supply. Once they are used up, they cannot be replenished on a human timescale. Examples include fossil fuels (coal, oil, natural gas), minerals (iron, copper, aluminum), and groundwater (in some areas).

It's important to note that even some renewable resources can be depleted if used unsustainably. For example, overfishing can lead to the depletion of fish stocks, even though they are theoretically renewable.