ISO
The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies from some 130 countries, one from each country.
The mission of ISO is to promote the development of standardization and related activities in the world with a view to facilitating the international exchange of goods and services.
ISO's work results in international agreements which are published as International Standards.

IEC
IEC (International Electrotechnical Commission) is the standardization organisation taking care of preparing and publishing international standards within the electric and electronic areas.

CEN
The preparation of harmonized standards within eg the non-active medical device sector is dealt with by to the European standardization organisation CEN.

CENELEC
The preparation of harmonized standards within eg the active medical device sector is dealt with by to the European standardization organisation CENELEC.