A standard is document, established by consensus and approved by a recognized body , that provides, for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achieve- ment of the optimum degree of order in a given context.
Standards play an important role in everyday life. They may establish size or shape or capacity of a product, process or system. They can specify performance of products or personnel. They also can define terms so that there is no misunderstanding among those using the standard.
As examples, standards help ensure that film to fit our cameras can be purchased anywhere in the world, that a light bulb fits a socket, and plugs for electrical appliances fit outlets. With standards, our homes, workplaces and public buildings are safer from collapse, fire and explosion.