basically at first you can build copper and bronze items with just the anvil but when you unlock it you can build a forge to unlock and make iron and eventually steel items it will also enhance copper and bronze crafting
i also have an idea how the smith with craft using it this scenario is for making a iron sword
- he grabs an iron ingot from the stockpile
- he puts it into the furnace and pumps the bellows abit
- he uses some tongs to grab the red hot metal and takes it to the anvil
- he hammers the metal abit
- he grabs wood from the stock pile and takes it to the anvil and crafts the sword like any other crafter
6.you get an iron sword
i know i sounds long written but it would be quite quick ingame evan at normal speed