A standard is a document that provides requirements, specifications, guidelines or characteristics that can be used consistently to ensure that materials, products, processes, and services are fit for their purpose.

ISO’s work programme ranges from standards for traditional activities, such as agriculture and construction, through mechanical engineering to the newest information and communications technology (ICT) developments, such as the digital coding of audio-visual signals for multimedia applications. It collaborates on ICT with partners like IEC (International Electrotechnical Commission) and ITU (International Telecommunication Union).

ISO standards are voluntary. ISO is a non-governmental organization and it has no power to enforce the implementation of the standards it develops. A number of ISO standards – mainly those concerned with health, safety or the environment – have been adopted in some countries as part of their regulatory framework, or are referred to in legislation for which they serve as the technical basis. However, such adoptions are decisions by the regulatory authorities or governments of the countries concerned. ISO itself does not regulate or legislate. Although voluntary, ISO standards may become a market requirement, as has happened in the case of ISO 9000 quality management systems, or ISO freight container dimensions.

ISO standards represent, by an international consensus among experts in the technology concerned, the state of the art. To ensure that ISO standards retain this lead, they are reviewed at least every five years after their publication. The technical experts then decide whether the standard is still valid, or whether it should be withdrawn or updated. In some fields, the pace of development is such that when an ISO standard is published, the experts who developed it are already thinking about the next version!