Potential Resources: Resources which are found in a region, but have not been utilised For example, the western parts of India particularly Rajasthan and Gujarat have enormous potential for the development of wind and solar energy, but so far these have not been developed properly.

Developed Resources: Resources which are surveyed and their quality and quantity have been determined for utilisation. The development of resources depends on technology and level of their feasibility.
Stock: Materials in the environment which have the potential to satisfy human needs but human beings do not have the appropriate technology to access these, are included among stock. For example, water is a compound of two gases; hydrogen and oxygen. Hydrogen can be used as a rich source of energy. But we do not have advanced technical ‘know-how’ to use it for this purpose. Hence, it can be considered as stock.