Universal Description, Discovery and Integration (UDDI) is a directory of web services where you can publish your own web services or search for existing web services. The directory could be global or could be local to the enterprise. UDDI is also a web service with operations supported for publishing and searching contents.
We will not be focusing on UDDI in this book, but you can visit http://docs.oracle.com/cd/E14571_01/web.1111/e13734/uddi.htm#WSADV226 for more information.