Charcoal

A purifying wooden fuel made in a kiln. Might be useful when extreme heat is needed.
Overview
Charcoal is a basic processed fuel material used in a wide range of crafting. It is a particularly important ingredient for casting at the 
Beyond its role at the Furnace, Charcoal also has several other uses, including in 


If Charcoal is being made only to support Furnace casting, a small setup is enough. Building one or two production buildings for it is generally sufficient for that purpose, since a modest supply can cover early smelting and casting needs without taking up much space or labor. When later recipes start consuming it for other goods, however, production should be increased so it does not become a bottleneck.
In practice, Charcoal is most valuable when kept in reserve for crafting chains that depend on refined materials. Its usefulness across several different systems means it is easy to underestimate at first, but it quickly becomes a material that links early resource processing to more advanced settlement development.
Official description
A purifying wooden fuel made in a kiln. Might be useful when extreme heat is needed.