A prescribed set of rules, conditions, or requirements concerning definitions of terms; classification of components; specification of materials, performance, or operations; delineation of procedures; or measurement of quantity and quality in describing materials, products, systems, services, or practices.
As late as 1927, green lights meant stop in some U.S. cities and go in others. There were frequent traffic accidents when travelers visited other cities.
A fire broke out in 1904 in Baltimore, Maryland. Special trains rushed fire equipment from Washington, New York, and Philadelphia. The fire destroyed approximately 2,500 buildings and burned for more than 30 hours...all because the hoses from the other cities would not fit the Baltimore hydrants.
By establishing standards, that everyone adopts, these situations can be prevented and manufacturers can be sure their products will be interchangeable with those of other manufacturers. Standards are everywhere - curriculum standards, sports equipment, crash worthiness for cars, weight limits for elevators, sizes (clothing, beds, bottles, football fields), seismic design for buildings, concrete mix, etc. The list is virtually endless.
(Information taken from: Through History with Standards published by the American Standards Association. It was also reprinted in Speaking of Standards (edited by Rowen Glie), published by Cahners Books in 1972, on pages 37-71.)