| 1. | Meaning | These are regularly replenished through natural process. | These exist on earth in fairly fixed quantities and can be depleted or exhausted. |
| 2. | Availability | Always available and have the potential to last indefinitely. | Limited supply and will eventually run out. |
| 3. | Replenishment | Naturally replenished. | Take millions of years to form. |
| 4. | Examples | Water, wind, sunlight, forests. | Coal, natural gas, petroleum, minerals. |
| 5. | Impact on Environment | Cleaner and better for the environment. | Cause more pollution and harm the environment. |