Some resources will run out, while others can be replaced. Using resources sustainably means thinking about future generations.
Finite resources
Used up faster than they can be replaced, so they will eventually run out.
Examples: fossil fuels and metal ores.
Renewable resources
Can be replaced at the same rate as, or faster than, they are used.
Examples: timber and biofuels.
Sustainable developmentMeeting the needs of people today without stopping future generations from meeting their own needs.
New ways of extracting metals from low-grade ores (phytomining and bioleaching) are in Reduce, Reuse & Recycle.