ISO 9000 is not a standard by itself, rather, it is a
family of
standards defined by the
ISO. The standards are referred to as ISO 9000 so as not to use confusing alternatives such as
ISO 9001/9002/9003 and
ISO 900x. ISO 9000, like
ISO 14000, is a family of standards and
guidelines related to managing
systems, as well as related supporting standards in
terminology and
tools.
Unlike many other ISO standards, ISO 9000 is a generic standard. This means it can be applied to any organization, regardless of size, products (or services), and purpose (enterprise, non-profit, government). ISO 9000 is a management system, meaning it deals with what an organization does to manage its processes. Having procedures increasingly benefits an organization as it gets larger. These procedures make an organization more efficient and effective.
ISO 9000 is primarily concerned with quality management. The term "quality" is subjective, but in the context of the standards, refers to the features in product or service that are required by the customer. Therefore, quality management is what an organization does to ensure its products or services fit the customer's requirements.
The standards deal only with how an organization performs its work, and not directly the products and services that result from this. ISO 9000 is not a product or service standard, and thus should not be used to gauge their quality.
It should be noted that there is no ISO 9000 certificate. ISO itself only creates standards, but does not perform assessments. There are other (third party) bodies that will perform this. Therefore, it is misleading to declare an organization as "ISO Certified" or "ISO Registered".
information from http://www.iso.ch/9000e