system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does charcoal burn if it’s already burnt?

I was watching a chef use charcoal in his restaurant and I realized I don’t know how charcoal works. To my understanding, charcoal is pre-burnt pieces of wood. So why does it burn so well?

Edit: Thank you everyone! Much appreciated 🙏🏽
gpt
Wood isn't just a single thing. It's lots of things. There are oils and water and other things than just carbon. And those other things don't burn very well.\*

Charcoal is made by heating wood in a low or no oxygen environment. The lack of oxygen prevents it from burning, while the heat causes things like water to evaporate and leave.

What you are left with is basically pure carbon which will burn much more efficiently with all those other impurities removed.

\*- as noted in some of the comments, some of the impurities *do* burn well and can be captured and used for other purposes.