A torch is, to put it simply, a piece of wood lit on fire. It can be used as permanent static lighting. There are a few ways to make torches, with later crafts aimed towards to conserving the number of sticks used.
Stats[]
2 [+2 fire debuff] (2 vs wall, turns into ashes)
Ways to Craft[]
Set a stick on fire.
stick + coal => 4 torches
stick + phosphorus => 8 torches
Builds into[]
Ashes (burn out a torch)