Resources can be classified in several ways, including by origin, exhaustibility, ownership, and development status. Biotic resources come from living things while abiotic resources are non-living. Renewable resources can replenish, like forests, while non-renewables deplete, like fossil fuels. Resources are also grouped by whether they are owned privately, by a community, or nationally. Potential resources have not been used yet, while developed resources have been surveyed and reserves can be accessed with current technology.