A resource is a source or supply from which benefit is produced. Typically resources are materials, energy, services, staff, knowledge, or other assets that are transformed to produce benefit and in the process may be consumed or made unavailable. Benefits of resource utilization may include increased wealth, meeting needs or wants, proper functioning of a system, or enhanced well being. From a human perspective a natural resource is anything obtained from the environment to satisfy human needs and wants. From a broader biological or ecological perspective a resource satisfies the needs of a living organism (see biological resource). The concept of resources has been applied in diverse realms, including with respect to economics, biology and ecology, computer science, management, and human resources, and is linked to the concepts of competition, sustainability, conservation, and stewardship. In application within human society, commercial or non-commercial factors require resource allocation through resource management. Resources have three main characteristics: utility, limited availability, and potential for depletion or consumption. Resources have been variously categorized as biotic versus abiotic, renewable versus non-renewable, and potential versus actual, along with more elaborate classification.