These are two or more intranet networks that are joined for the purpose of sharing information. If two companies link their intranets, they would have an extranet. By definition, extranets are proprietary to the organizations involved. Companies participating in an extranet have formed a structural bond, the third and strongest level of relationship marketing. The use of extranets allows CRM to integrate with and supply chain management (SCM). Extranets are not accessible to everyone as they are password protected.