WHAT DOES WOOD PELLET FUEL MEAN?

I'm explained to I may have more than I want, My response is I would prefer to have enough for 3 a long time than not have sufficient to complete 1 yr.Ouch. The amount is fuel oil for every gallon? The only real calendar year I burned pellets exclusively was when fuel oil prices went outrageous in New England. I believe I burned about 30 gallons th