Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses.
As a unit of mass, ton can mean:
the long ton, which is 2,240 pounds (1,016.0 kilograms)
the short ton, which is 2,000 pounds (907.2 kilograms)
the tonne, also called the metric ton, which is 1,000 kilograms (about 2,204.6 pounds) or 1 megagram.
Its original use as a unit of volume has continued in the capacity of cargo ships and in units such as the freight ton and a number of other units, ranging from 35 to 100 cubic feet (0.99 to 2.83 m3) in size. Recent specialized uses include the ton as a means of truck classification. It can also be used as a unit of energy, or in refrigeration as a unit of power, sometimes called a ton of refrigeration.
Because the ton (of any system of measuring weight) is usually the heaviest unit named in colloquial speech, its name also has figurative uses, singular and plural, informally meaning a large amount or quantity, or to a great degree, as in "There's a ton of bees in this hive," "We have tons of homework," and "I love you a ton."
