This book offers an in-depth analysis of the function of certification in general and of certification systems in a range of different sectors. The authors examine certification from both a theoretical and a practical standpoint and from the perspectives of different disciplines, including law, economics, management, and the social sciences. They also discuss instruments that help ensure the quality of certification, which can range from public law measures such as accreditation, to private law incentives, to deterrents, such as liability towards victims. Further, they assess the role of competition between certification bodies. Readers will learn the commonalities as well as the necessary distinctions between certification bodies in various fields, which may stem from the different functions they serve. These similarities and differences may also be the result of different types of damage that the certified producer or service provider could potentially cause to individuals or to the public at large. Often, companies use certification bodies as an argument to assure the general public, e.g. regarding the safety of medical products. Closer inspection reveals, however, that sometimes certification bodies themselves lack credibility. The book offers essential information on the benefits and pitfalls associated with certification.