The cord is a unit of measure of dry volume used to measure firewood and pulpwood in the United States and Canada.
A cord is the amount of wood that, when "racked and well stowed", occupies a volume of 128 cubic feet. This corresponds to a well-stacked woodpile 4 feet high, 8 feet long, and 4 feet deep; or any other arrangement of linear measurements that yields the same volume.
The name cord probably comes from the use of a cord or string to measure it.
Cord-foot was a US unit of volume for stacked firewood, four feet long, four feet wide and one foot high - equal to one eighth of a cord. Symbol for the unit was cd-ft.