Originally posted by Pradeep Bhat: What are the other protocols that could possibly be used in Web Services?
SOAP is pretty much the core of web services. If you're using, say, XML-RPC instead of SOAP then you wouldn't be using web services but XML-RPC... Of course, sometimes the term "web services" is used in a very general sense where it can mean "any XML messaging over HTTP" or even "we have a web site which provides services to our customers"
SOAP introduces processing overhead with even the most rudimentary message exchanges, but there really are no viable alternatives. All of the major vendors are standardizing on SOAP, and many of the Web Services specifications are implemented as SOAP headers.