The Universal Description, Discovery and Integration (UDDI) specifications define a registry service for Web services and for other electronic and non-electronic services. A UDDI registry service is a Web service that manages information about service providers, service implementations, and service metadata. Service providers can use UDDI to advertise the services they offer. Service consumers can use UDDI to discover services that suit their requirements and to obtain the service metadata needed to consume those services.
The UDDI specifications define:
SOAP APIs that applications use to query and to publish information to a UDDI registry
XML Schema schemata of the registry data model and the SOAP message formats
WSDL definitions of the SOAP APIs
UDDI registry definitions (technical models - tModels) of various identifier and category systems that may be used to identify and categorize UDDI registrations
The OASIS UDDI Spec TC also develops technical notes and best practice documents that aid users in deploying and using UDDI registries effectively.
A business may deploy one or more private and/or public UDDI registries. A private registry permits access to only authorized users. A public registry does not restrict access to the registry. A business may choose to deploy multiple registries in order to segregate internal and external service information. An internal registry supports intranet applications, while an external registry supports extranet applications. Industry groups may deploy a UDDI registry to support public or private exchanges.
UDDI is complementary to other Web services-related projects at OASIS and W3C, such as SOAP, WSDL, WSBPEL, WSRP, and WS-Security. WS-I adopts and further profiles the UDDI V2.0 standard in the WS-I Basic Profile.