Renewable vs Non-Renewable Resources
Here's the crucial difference: non-renewable resources like oil, gas, and coal will all run out eventually - oil might last 50 years, gas about 60 years, and coal roughly 400 years. They also cause serious environmental damage.
Renewable resources never run out and cause much less environmental harm, though they're not perfect. The trade-off is that they currently provide less energy and can be unreliable, especially weather-dependent sources like solar and wind.
Most of our energy still comes from fossil fuels, but this will have to change as supplies dwindle and climate change pressures increase.
Reality Check: We're still getting about 80% of our energy from sources that will eventually run out - that's why renewable energy matters so much!