The core component of the UDDI project is the UDDI business registration database. This is really a large XML file that describes a business entity and any Web services that exist within that entity. The UDDI Business Registry can be used at a business level to determine if a particular trading partner has a specific Web service interface. You can locate companies in a given industry that provides a particular type of service, for instance: Airlines ->
The folks that wrote the UDDI specification describe UDDI as the next layer on the stack, with Simple Object Access Protocol (SOAP) below it, and Extensible Markup Language (XML) below that and above native network protocols (HTTP and TCP/IP). The UDDI spec describes a conceptual cloud of Web services, as well as an API (application programming interface) to define a simple framework for describing any kind of Web service. The spec is made up of several documents including an XML schema that defines a SOAP-based API for both registering and finding Web services.
Using the UDDI discovery services allows entities to register information about the Web services that are exposed for use by other Internet connected businesses. By doing this, information is added to the UDDI business register through a Web interface or through a defined registry protocol. The UDDI business registry is a distributed database, which provides virtual centralization. There are multiple root nodes that synchronize data in near-time, allowing businesses to register with one database, and have that information available in all UDDI databases within minutes. UDDI is taking this approach due to the large number of entities that may be using the databases at a single point in time, as well as protection against database failure.
Once the information is inside of the registry, other UDDI-enabled programs, or UDDI aware programmers, can both discover and utilize Web services. Using this mechanism the partner can determine if the service exists and is compatible with native enterprise systems. You may locate specific services through UDDI directly, or though online marketplaces and search engines that are able to peek into UDDI databases as a data source. As we move forward, the UDDI gang is promising that this will be more of an automated process. It matters not whether or not this occurs inside the firewall, or outside. Nor does it matter which enabling technology you employ (Web servers, etc.)
This was first published in May 2003