What is exactly 1 ton?

Could you please elaborate on the precise meaning of '1 ton'? I'm curious to know the exact definition and how it's measured. Is it a unit of mass or weight? How does it compare to other units like kilograms or pounds? Additionally, in what contexts is the term '1 ton' commonly used? Is it primarily in the shipping industry, construction, or some other area? I'm eager to gain a deeper understanding of this measurement and its practical applications.