Accreditation is a review process to determine if companies meet defined standards of quality. Once achieved, accreditation is not permanent—it is renewed periodically to ensure that the quality of the quality program is maintained.
According to ISO17011:2004 Accreditation means: Third–party attestation related to a conformity assessment body conveying formal demonstration of its competence to carry out specific assessment tasks.
Third-party conformity assessment bodies perform certification of management systems, a third-party conformity assessment activity.