Lighterwood, Fatwood it is all the same thing. Pine wood completely soaked with dried pine sap.

Here in the south we have pine forests and old timber. Old timber has hardwoods. Pine forests are good for harvesting to make wood products like 2x4's but losey for burning. Except the stumps.

The sap in the wood is stable and will not evaporate or ooze on to your gear. A splinter 1/4 the size of a pencil about finger length will easily light with a match and burn for several minutes with a large flame. Even soaked in water for several hours, it will easily light with a cotton ball. The sap burns and once consumed, the wood burns. A very good tinder to carry.

We don't have no birch, aspen, or mesquite. We have oak, maple and pine. Pine grows in strong sun. It creates shade so the maple and oak can grow. You can tell how old a stand of timber is by the percentage of hardwoods to pine. You burn maple and oak to make fire with little smoke and great coals. You burn pine to make smoke or because it is the only wood around.

There are stories of people who have found fatwood stumps and will not tell because it is highly prized. I will tell because it is in my backyard and no one can collect without my approval anyway. Any proper Southener would give you some as a show of courtesy but would not tell you where their personal stash is. Would you like some sweet tea?