Web services opens up a new world of interaction in which servers can start talking to other servers. The two main protocols for working with web services are REST and SOAP. REST is newer and simpler than SOAP. Its simplicity is based on the fact that it assumes the existence of HTTP, using HTTP’s protocols to request and get back information.
SOAP has been around longer and specifies both an XML packaging for XML data and a set of rules with which SOAP servers must comply when communicating.
Next, we’ll look at how we can advertise our web service using the Web Services Description Language (WSDL).