SOAP
is a XML-based protocol to get an access for web services and it was the recommendation given by W3C to give the communication for an applications, the advantage of SOAP is that it's a platform and language independent and one more advantage is interacting with an applications which were developed in other language coding. SOAP uses WSDL.
SOAP incorporates an inherent arrangement of standards for encoding information sorts. It empowers the SOAP message to show particular information sorts, for example, integers, arrays, etc.
The UDDI
is a distributed registry of web services, it is an open framework and platform independent, UDDI uses RMI and SOAP to communicate, UDDI also uses WSDL. UDDI also a XML based standard.
The WSDL
is called as wiz-dull, where SOAP and UDDI uses WSDL protocol, the definitions of WSDL are used to describe web services and it is also a XML based registry.