Whats the difference between a Seasoned Log & Unseasoned Log?

Unseasoned logs are logs that have been freshly cut and likely to have a high moisture content – i.e. above 50%. A seasoned log however, has been cut and stored for a long period of time so that the moisture content is considerably less – between 25% and 50%.  Because of the lower moisture content seasoned logs will burn hotter and more efficiently than unseasoned logs.  For the same reason Kiln Dried Logs with 20% moisture or less, burn hotter and more efficiently still.