Ton is a unit of mass in different measurement systems and usually mistaken with each other. The short ton (also known as net ton) equals to 2000 pounds and used in north america (united states and canada), the long ton (also known as weight or gross ton) is used in the imperial system (UK and some of the other english speaking countries) and defined as 2240 pounds or 1016 kilograms. The metric ton (also known as tonne) equals to 1000 kilograms and used in the metric system. The abbreviation is "T".
If you are trading internationally, you must know what type of ton as a weight unit is used in that country to avoid the surprises.
Pound is a unit of mass in the imperial and U.S. customary measurement systems. International avoirdupois pound is defined as 0.45359237 kilograms. Troy pound is rarely used. There are 16 ounces in a pound and 12 troy ounces in a troy pound. The abbreviations are "lb", "lbs".