Standards are documented agreements containing technical specifications or other precise criteria to be used consistently as rules, guidelines, or definitions of characteristics, to ensure that materials, products, processes and services are fit for their purpose. They are documents that have been developed and approved in accordance with established standardization procedures and applies collectively to regulatory standards, test methods, and voluntary industry standards.
Engineers, inventors, manufcturers and contractors, insurers, governmental bodies, attorneys and consumers (like homeowners) all rely on standards to assure that buildings, bridges, cars, roads, al all sorts of products and goods are safe and usable--and that the people responsible for their design, production, and construction can be held accountable.
Probably the most significant standard ever developed in the United States, however, was the railroads' standard track gage. This standard, now used in Great Britain, the U.S., Canada and much of continental Europe, enables railroad rolling stock to cross the country.