Topic: Java EE (Enterprise), Enterprise JavaBeans
SOAP is basically an XML marshalling mechanism for RPC calls. It doesn't specify a transport although it is most commonly used with HTTP. It could also be used to encode an RPC call over a simple TCP/IP socket or a JMS message. People have a tendency to use the latest technology for no other reason than 'just because'. This article gives the reasons why SOAP may be appropriate in conjunction with session beans and when it makes little sense. See more in this article by Billy Newport on theserverside.com.